Policy 11-3-4: Chemical Hygiene Plan
Policy: | Policy 11-3-4: Chemical Hygiene Plan | Date Adopted: | ||
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Department: | Environmental Health & Safety | Contact: | Environmental Health and Safety Coordinator | |
Statement: | This Chemical Hygiene Plan (CHP) for the Western Nevada College (WNC) establishes guidelines for laboratory operations to minimize the potential for chemical exposures that may adversely affect personnel health and safety. Additionally, this CHP is designed to comply with Title 29 of the Code of Federal Regulations (CFR) 1910.1450, "Occupational Exposure to Hazardous Chemicals in Laboratories", commonly referred to as the Occupational Safety and Health Administration (OSHA) Lab Standard. |
Table of Contents:
- Scope
- Responsibilities
- House keeping
- Laboratory Assessments
- Personal Chemical Hygiene
- Standard Operating Procedures
- Control Measures
- Exposure Monitoring
- Hazard Communications
- Chemical Storage
Section 1: Scope
- The OSHA Lab Standard applies to all workplaces engaged in the laboratory use of hazardous
chemicals. Laboratory use of hazardous chemicals is defined as the handling or use
of hazardous chemicals in which all of the following criteria are met:
- Procedures using chemicals are carried out on a laboratory scale (e.g. using containers for reaction, transfers, and other handling of chemicals that are easily manipulated by one person).
- Multiple chemical procedures or chemicals are used.
- The operations involved are neither part of a production process nor simulate one.
- Protective laboratory practices and equipment are available and are commonly used to minimize the potential for personnel exposure to hazardous chemicals.
- When the operations in a particular facility meet all of the above criteria, that facility must comply with the requirements of this CHP. Other workplaces that use or store hazardous chemicals must comply with the WNC Hazardous Waste Management Policy and the WNC Hazardous Communication Program.
- Research and teaching laboratories that utilize hazardous chemicals are examples of workplaces where this standard is applied. Examples of workplaces not covered by the OSHA Lab Standard are quality control labs, electronic labs, photo labs, nursing labs, automotive shops, welding shops, and machine shops.
Section 2: Responsibilities
- Environmental Health and Safety Department (EH&S)
- The Environmental Health and Safety Department (EH&S) is an administrative unit under the Vice President for Administrative Services and General Council that has responsibility for development and implementation of WNC environmental health and safety policies.
- Chemical Hygiene Officer (CHO).
- A staff member of the Environmental Health and Safety Department is designated as
the College Chemical Hygiene Officer (CHO). Responsibilities of the College CHO include:
- Administration and implementation of the WNC Chemical Hygiene Plan (CHP).
- Assisting Laboratory Supervisors in development and implementation of laboratory-specific SOPs and work practices.
- Ensuring that appropriate laboratory assessments are conducted to ensure implementation of this program.
- Reviewing the WNC CHP annually.
- Determining if exposure monitoring is necessary.
- Determining if medical surveillance is necessary.
- Reviewing chemical procedure with ones CHO as required.
- The WNC designated CHO will use University of Nevada Reno expertise as required.
- Chemical Hygiene Contacts
- WNC Environmental Health & Safety Officer
Brian Crowe (acting as College CHO)
775-445-3327
775-291-1355 (cell) - In the event the WNC designated CHO is unavailable, employees should contact the Vice President for Administrative Services and General Council (775-445-4231) to obtain assistance regarding a chemical concern.
- WNC Environmental Health & Safety Officer
- A staff member of the Environmental Health and Safety Department is designated as
the College Chemical Hygiene Officer (CHO). Responsibilities of the College CHO include:
- Academic Departments
- The Academic Director has ultimate responsibility for environmental health and safety issues within his or her division. It is the Academic Directors responsibility to ensure that all division faculties understand their responsibilities and is committed to implementation of the CHP. Additionally, it is the Academic Directors responsibility to determine what division operations are governed by the OSHA Lab Standard, and to ensure that such operations comply with this CHP. To facilitate this process, the Academic Director will appoint a division chemical hygiene officer or an academic team.
- It is necessary that the EH&S Department work closely with the Division Chemical Hygiene Officer, ot team, on all aspects of the Chemical Hygiene Plan.
- Similarly the Division Chemical Hygiene Officer, or team, must work closely with all
involved faculty on all campuses to ensure plan viability and compliance. The WNC
Division Chemical Hygiene Officer is responsible for:
- Providing technical guidance and assistance to department faculty and staff in implementation of this CHP.
- Ensuring an inventory of chemical hazards (by location) in the department is maintained and readily accessible to emergency responders.
- Performing (in conjunction with the college CHO) health and safety assessments of division laboratories.
- Serving as the division contact for chemical hygiene related issues.
- Promoting good chemical hygiene practice in their division.
- Lab Supervisor
- Lab Supervisors are responsible for the health and safety of all personnel working
in their laboratory (teaching labs). The WNC CHP serves as a vehicle for improving
laboratory safety. Lab Supervisors are responsible for implementing the WNC CHP in
their lab(s). Specific responsibilities include:
- Reviewing and approving planned laboratory activities and the hazardous chemicals involved.
- Developing written Standard Operating Procedures (SOPs) for their laboratory operations that involve hazardous chemicals.
- Ensuring that personnel under their supervision receive appropriate training as required by the CHP.
- Ensuring that appropriate engineering controls (such as laboratory hoods) and personal protective equipment (such as gloves and protective eyewear) are available and in working order, and that employees and students have been trained in the proper use of such equipment.
- Ensuring chemical waste generated by their laboratory is minimized and that such waste is disposed of properly.
- Performing periodic chemical safety and housekeeping assessments and initiating any necessary corrective action.
- Maintaining a current chemical inventory of hazardous chemicals in their laboratory.
- Maintaining the following documents within the laboratory in a common location (perhaps
a notebook(s)) that is easily identifiable and accessible to laboratory personnel:
- College Chemical Hygiene Plan (this document).
- Inventory of hazardous chemicals in the laboratory, and have proper MSDS, or HDS, in the laboratory
- Laboratory-specific SOPs.
- Completed laboratory assessment forms.
- Laboratory safety training records (e.g., a signed training outline).
- Contact
- Dr. Elizabeth Tattersall-Lab Supervisor- Douglas Campus
- Renee Magrini-Lab Supervisor- Bristlecone 329
- Dr. Gary Evett-Lab Supervisor- Virgil Getto Hall Fallon
- Dr. Steve Carman- Lab Supervisor Aspen 201
- Randy Brown Nursing Lab Coordinator Cedar second floor
- Lab Supervisors are responsible for the health and safety of all personnel working
in their laboratory (teaching labs). The WNC CHP serves as a vehicle for improving
laboratory safety. Lab Supervisors are responsible for implementing the WNC CHP in
their lab(s). Specific responsibilities include:
- Laboratory Workers
- All laboratory workers (employees and/or students) are responsible for their own safety
as well as the safety of other laboratory workers. Unsafe acts performed by one individual
can affect (directly or indirectly) the safety and work productivity of others. Personnel
who have health or safety concerns should contact their supervisor and/or EH&S and
should not perform the work until they are confident their concerns have been adequately
addressed. Specific responsibilities include:
- Conducting all laboratory activities in accordance with the WNC CHP and laboratory-specific standard operating procedures.
- Participating in required training.
- Utilizing engineering controls, safety equipment, and personal protective equipment in an appropriate manner.
- Informing the laboratory supervisor of any accidents or unsafe conditions.
- All laboratory workers (employees and/or students) are responsible for their own safety
as well as the safety of other laboratory workers. Unsafe acts performed by one individual
can affect (directly or indirectly) the safety and work productivity of others. Personnel
who have health or safety concerns should contact their supervisor and/or EH&S and
should not perform the work until they are confident their concerns have been adequately
addressed. Specific responsibilities include:
Section 3: House keeping
- An unorganized, cluttered laboratory increases the likelihood of chemical spills and splashes due to tripping or knocking over of chemical containers. Safety equipment such as fire extinguishers, safety showers, and eyewashes can prevent or minimize harm to personnel; however they are ineffective if access to this equipment is blocked. Organize your laboratory so that clear walkways are provided, with designated storage areas for chemicals and hazardous waste; avoid clutter that can prevent access to safety equipment or which can lead to chemical spills.
- Wash lab benches with disinfectant and paper towels before you start your experiments.
- Wash your hands after youve washed your lab bench area.
- Wipe off all bottles after use; replace lids and stoppers immediately after using them; do NOT hand the bottles to your co-worker without a lid or stopper. Know where the fire extinguisher is that is located in the lab. Remember to STOP, DROP, AND ROLL.
Section 4: Laboratory Assessments
- A formal health and safety assessment of chemical laboratories and chemical storerooms will be conducted at least once per year. The WNC Chemical Hygiene Officer (and/or other EH&S staff as appropriate), applicable Division Chemical Hygiene Officer, or team, and other interested personnel will perform these assessments. Results of these assessments will be given to the Laboratory Supervisor and the Academic Director, with records of these inspections maintained by the applicable Department and EH&S.Additionally, Laboratory Supervisors are to perform self-assessments of their own laboratory at least twice per year, spaced approximately evenly between the yearly formal inspection.The purpose of these self-assessments is to allow the Laboratory Supervisor to self-identify and correct safety and health weaknesses. The Laboratory Supervisor shall maintain records of these assessments.
Section 5: Personal Chemical Hygiene
- Good personal chemical hygiene habits minimize chemical exposure. Consuming food,
beverages, tobacco (smoking or smokeless), or applying cosmetics while in laboratories
or chemical storage areas provides a route of chemical exposure through ingestion.
For the same reason, do not store food or beverages in laboratories (including refrigerators)
or chemical storage areas. Washing your hands frequently will minimize chemical exposure
through ingestion and direct contact with the skin. Always wash hands before eating,
drinking, smoking, or applying cosmetics.
- Injectables means substances thatstudents bring on campusfor medication (parenteral) purpose and not for learning techniques such as stating IVs, performing IM, SQ, ID injections or venipuncture techniques or techniques not covered or described that arerequired didactically.Injectables are not allowed in labs.
- Long hair needs to be put up out of the way. It is the faculty members and students responsibility.
- Wash glassware at the end of the day and place return clean glassware to its proper location.
- Throw paper towels in the trash; turn off hot plates.
- Clean off all metal utensils and equipment youve used. Return utensils and equipment to their proper location.
- Wash your lab bench with disinfectant and paper towels when youve completed your lab experiments.
- Make no other plans during the time allotted for your experiments.
- Wash your hands as you leave for the day, AND THEN pick up your items at the front of the lab as you leave.
- Wash your hands when leaving to take, or are returning from, a break.
- Perform no unauthorized experiments.
- Follow your lab safety training when dealing with broken glass or chemical spills.
- Personnel Contamination
- Quick response to personnel contamination is necessary to minimize harm to the affected
individual. To reduce response time, be aware of what chemicals are being used in
the laboratory, and where eyewashes and safety showers are located.
- If chemical contact with the eyes or skin occurs, immediately flush the affected area using water (eyewash, emergency shower, or other means available). Never use anything other than water to wash contaminated personnel (unless specifically directed to do so by medical personnel). It is recommended that the affected area be flushed for at least 15 minutes. (The only exception is a 4, 9, 18 M solution of sulfuric acid H2SO4 which should be initially treated with a phosphate buffer rinse then additional flushing with water). Note: Remove clothing and jewelry as necessary to rinse all potentially affected areas.
- Due to pain and irritation, the eyes may have to be physically held open (by using your hands and/or a gauze pad) during flushing. Do not try and remove contact lenses before flushing the eyes. If not removed by the flushing water, contact lenses should be removed as soon as the eyes can be held comfortably open.
- Personnel with chemical exposure to the eyes should always seek immediate medical attention. Personnel with skin exposure to hydrofluoric acid, phenol, or other severe skin contact hazards should also seek immediate medical attention. Additionally, seek medical attention if pain, numbness, redness, irritation or other signs are apparent.
- Note: Provide medical personnel with MSDS, the SDS, or other sources of health hazard information for the chemical(s) involved.
- Report all incidents of personnel contamination to the lab supervisor or your instructor. Lab supervisors and instructors shall assure that incident reports on all personnel contamination incidents are sent to EH&S.
- Quick response to personnel contamination is necessary to minimize harm to the affected
individual. To reduce response time, be aware of what chemicals are being used in
the laboratory, and where eyewashes and safety showers are located.
Section 6: Standard Operating Procedures
- Written Procedures
Written Standard Operating Procedures (SOPs) relevant to health and safety concerns are required for laboratory operations involving hazardous chemicals. This document contains SOPs covering various chemical hazard classes. Laboratory Supervisors are responsible for developing additional laboratory-specific SOPs that cover hazards specific to their laboratory. Laboratory-specific SOPs should target the use of particularly hazardous chemicals, frequently performed procedures, and chemicals that are used frequently or in relatively large amounts. These laboratory-specific SOPs are an important component of the WNC Chemical Hygiene Program (CHP).- All laboratory SOPs must be approved by the Academic Director.
- The following items should be considered when developing a SOP:
- Identify chemicals to be used (as well as reaction products or intermediates produced) and the volume, frequency, and duration of use.
- Identify and evaluate health and physical hazards associated with the procedure. Identify routes of exposure, type and level of toxicity, target organs, and effects. Consult MSDS/SDSs other references, and EH&S as necessary.
- Identify workers susceptible to any of the chemicals used (such as pregnant workers when reproductive toxins (teratogens) are to be used).
- Select appropriate control methods for the identified hazards.
- Prepare for contingencies such as spills or unexpected reactions.
- SOPs can be incorporated into lab protocols or they can be written as separate documents.
The format of the SOPs can vary depending on need. For example, the scope of an SOP
can cover:
- The generic use of a specific chemical or class of chemicals with similar hazards (for example, mineral acids).
- The specific use of a chemical or class of chemicals (such as a specific procedure).
- A generic procedure (such as distillation) that utilizes several chemicals.
- General Laboratory Rules and Procedures
- KNOW THE HAZARDS OF THE CHEMICALS YOU ARE WORKING WITH!Consult the Material Safety Data Sheet or Safety Data Sheet (MSDS) or other appropriate references prior to using a chemical with which you are unfamiliar.
- Minimize exposure to all chemicals regardless of toxicity or their familiarity. Most laboratory chemicals have not been fully characterized with respect to their toxicity. It is therefore prudent to implement procedures that will reduce the likelihood of exposure. SKIN CONTACT SHOULD ALWAYS BE AVOIDED! AVOID INHALATION OF CHEMICALS; never sniff to test chemicals.
- Avoid horseplay, games, and other behavior that can lead to accidents.
- Wear appropriate eye protection at all times. At a minimum, goggles with indirect venting are required whenever operations involving chemicals are being performed.
- Communicate with others in the building when working alone in the laboratory; let them know when you arrive and leave. Avoid working alone in the laboratory when performing high hazard operations.
- When leaving unattended operations: I) post signs to communicate appropriate warnings and precautions, II) anticipate potential equipment and facility failures and III) provide containment for release of hazardous chemicals.
- Assume that unknown materials are toxic, and that a mixture is more toxic than its most toxic compound.
- Use appropriate safeguards for each chemical, including personal protective equipment.
- Do not use mouth suction for pipetting or siphoning.
- Know the location and proper use of emergency equipment, such as safety showers and fire extinguishers.
- Always use appropriate safety carriers (secondary containment) when transporting chemicals either inside or outside of the building.
- Selection of Chemicals
Prior to selecting a chemical for use in an operation or process, evaluate its use as follows:- Review the potential hazards of the substance to assess the conditions under which the compound will be used.
- Determine if a less hazardous chemical can be used for the operation. This determination should take into account the overall hazard of the chemical (such as toxicity, flammability, volatility, etc.).
- Determine if the chemical can be obtained from another laboratory. This will reduce chemical inventories and future waste disposal.
- Order only the volume of chemical needed, or that will be used in within the shelf life of the chemical.
- Determine if proper storage is available for the specific chemical to be used.
- Determine proper waste disposal and make sure appropriate waste containers are available.
- Toxic Chemicals
For many laboratory chemicals the greatest risk of exposure is via inhalation. Airborne exposure limits have been established for many chemicals. Although exposure limits are not a strict delineation between safe and unsafe conditions, exposure to chemicals at concentrations below these limits is generally considered safe.- Personnel exposure to hazardous chemicals must not exceed the applicable Occupational
Safety and Health Administration (OSHA), Permissible Exposure Limit (PEL), or the
American Conference of Industrial Hygienists (ACGIH) Threshold Limit Value (TLV),
whichever is most conservative.
- PELs can be found in MSDS/SDS 29 CFR 1910.1000, or can be obtained from EH&S. OTE: OSHA is currently revising some PELs, therefore all parties should double check the PELs given on lab documents with the figures on the OSHA website.
- TLVs can be found in MSDS/SDS the ACGIH TLV Booklet, or can be obtained from EH&S.
- Note: Exposure limits are most likely to be exceeded when performing operations outside of a lab hood, when using highly volatile chemicals, large volumes of chemicals, or chemicals with low exposure limits (such as less than 10 ppm).
- EH&S is responsible for performing chemical air monitoring. Contact the EH&S CHO to request air monitoring in your workplace.
- Chemicals having a PEL or TLV less than 50 ppm (or 0.25 mg/m3 for airborne particulate)
should be used in an operating laboratory hood or other device that effectively controls
exposures.
- If a TLV, PEL or comparable value is not available for a chemical, use animal or human toxicity data to assess the hazard. Chemicals meeting the definition of toxic should be used in a laboratory hood or similar device that effectively controls exposures.
- Personnel exposure to hazardous chemicals must not exceed the applicable Occupational
Safety and Health Administration (OSHA), Permissible Exposure Limit (PEL), or the
American Conference of Industrial Hygienists (ACGIH) Threshold Limit Value (TLV),
whichever is most conservative.
- Particularly Hazardous Substances
Extra precautions are required when working with particularly hazardous substances. Particularly hazardous substances include carcinogens, reproductive toxins, and chemicals with high acute toxicity (defined as highly toxic). Additionally, many chemicals are classified as suspect carcinogens since they show some carcinogenic activity but do not demonstrate unequivocal evidence of an increased risk of cancer in humans.The following references provide lists of substances classified as carcinogens and suspect carcinogens; however, exclusion from this list does not guarantee that a substance does not possess carcinogenic activity.
International Agency for Research on Cancer (IARC)
National Toxicity Program (NTP)
List of Chemicals Known to the State of California to Cause Cancer or Reproductive Toxicity
National Institute for Occupational Safety and Health (NIOSH) Carcinogen List
Ohio State UniversityThe procedures described in this section are designed to minimize exposure to personnel and are to be implemented when performing laboratory work with any chemical considered particularly hazardous. Suspect carcinogens are to be handled using these procedures when using large quantities (relative to normal laboratory scale) of material or under other conditions with increased likelihood of exposure (such as, generation of vapor or aerosol outside of a laboratory hood or other containment).- Work with particularly hazardous substances in a designated area.
- A designated area can be the entire laboratory, a specific laboratory workbench, or a laboratory hood.
- The designated area must be clearly marked with signs that identify the chemical hazard and include an appropriate warning, such as: WARNING! BENZENE WORK AREA CARCINOGEN.
- Access to the designated area must be controlled and limited to authorized and trained personnel.
- Prior to working in a designated area, personnel must receive training on the hazards
present in the area. Training should include:
- Engineering controls, procedures, and personal protective equipment used to minimize exposure.
- Contamination control methods for personnel, equipment and the facility.
- Spill response.
- All training provided to personnel shall be documented and maintained by the Laboratory Supervisor.
- Use the smallest amount of chemical that is consistent with the requirements of the work to be performed.
- It is recommended that a record of the amount of these substances used, the date of use, and the name of the user should be maintained.
- Use containment devices (such as lab hoods or glove boxes) when: (I) volatilizing
these substances, (II) manipulating substances that may generate aerosols and (III)
performing laboratory procedures that may result in uncontrolled release of the substance.
- Use High Efficiency Particulate Air (HEPA) filters, carbon beds, or scrubber systems with containment devices to protect effluent and vacuum lines, pumps, and the environment whenever feasible.
- Personnel protective equipment appropriate for the specific hazards must be used when
handling these substances.
- Gloves that provide personal protection from the chemical being used are to be worn whenever transferring or otherwise handling these substances.
- Do not wear jewelry when working in designated areas.
- On leaving a designated area, workers must remove any personal protective equipment worn and thoroughly wash hands, forearms, face, and neck.
- After each use (or day), the immediate work area and equipment are too wiped down
to prevent accumulation of chemical residues.
- At the end of the project, the designated area must be thoroughly decontaminated before resuming normal laboratory work in the area.
- Waste must be collected in a compatible container with a secure lid. Liquid waste must be kept in a leak-proof container inside a secondary container.
- Work with particularly hazardous substances in a designated area.
- Research Materials
Research materials include newly synthesized chemicals and chemical reaction byproducts whose identity or hazard characteristics are unknown. These materials must be labeled as described in section 9.1.2.- Research materials are assumed to be hazardous (and within the scope of this CHP) until the chemical has been identified and it is determined that the chemical is not hazardous (see Definition of hazardous chemical).
- A conservative approach should be taken with regard to exposure to research materials.
Exposure by all routes (inhalation, ingestion, skin contact, and injection) should
be minimized.
- Use the smallest amount of material necessary to perform the work planned.
- Work with research materials in a laboratory hood or other containment whenever possible.
- Avoid all skin contact; wear chemical resistant gloves when handling research materials.
- Flammable Substances
In general, the flammability of a chemical is determined by its flash point. Chemicals with flash points less than 200 F are considered to be potential fire hazards and should be handled with caution.- Flammable chemicals should be used only in vented hoods and away from sources of ignition.
Combustible chemicals should be used away from ignition sources, and in vented hoods
whenever possible.
- Never heat flammable chemicals with an open flame.
- For highly flammable chemicals, static electricity or hot surfaces can serve as ignition sources.
- Do not use electrical devices with cracked or frayed electrical wiring.
- Transfer flammable liquids from containers of five gallon-capacity or less inside a laboratory hood (or other area with similar ventilation) to prevent accumulation of a flammable concentration of vapors.
- Transfer flammable liquids from containers of greater than five gallon-capacities, in a well-ventilated area, outside the laboratory building or in an approved flammable storage room.
- When transferring flammable liquid from a container greater than one gallon, the containers must be electrically bonded and grounded.
- Fire extinguishers appropriate for the fire hazards present must be available in all
laboratories and storage areas.
- Class D fire extinguishers must be available in the immediate work area when working with flammable metals such as magnesium, sodium, and potassium.
- Flammable chemicals should be used only in vented hoods and away from sources of ignition.
Combustible chemicals should be used away from ignition sources, and in vented hoods
whenever possible.
- Reactive Chemicals
- Reactive chemicals are those that have the potential to vigorously polymerize, condense,
or become self-reactive due to shock, pressure, temperature, light, or contact with
another material. Examples of reactive chemicals are explosives, peroxides, water-reactives,
and pyrophorics.
- Handle reactive chemicals with caution, including segregation in storage and prohibition of mixing even small quantities with other chemicals without appropriate personal protection and procedures.
- Chemical reactions conducted at temperatures or pressures above or below ambient conditions must be performed in a manner that minimizes hazards such as explosion or vigorous reaction.
- Minimize the number of reactive chemicals in the laboratory and the volume of any one chemical to the smallest amount required for the work to be performed.
- Utilize shields and barricades, and personal protective equipment (such as face shields with throat protectors and heavy gloves) whenever there is a reasonable possibility of explosion or vigorous chemical reaction.
- Glass equipment operated under vacuum or pressure must be shielded, wrapped with tape, or otherwise protected from shattering.
- Glass equipment operated under vacuum or pressure must be shielded, wrapped with tape, or otherwise protected from shattering.
- Peroxides
Organic peroxides are explosive with extreme sensitivity to heat, impact, friction, light, and oxidizing and reducing compounds. Additionally, organic peroxides are highly flammable.- Do not use metal spatulas, stirring bars, or other metal items to handle peroxides as metal contamination can lead to explosive decomposition.
- Avoid friction, grinding, and other types of impact near peroxides (especially solid peroxides). Glass containers with screw-cap lids or glass stoppers should not be used for storage of peroxides. Polyethylene bottles with screw-cap lids can be used.
- After each use, carefully wipe the container neck, cap, and threads with a cloth or paper towel before resealing.
- Clean up all peroxide spills immediately.
- Contact EH&S at 775-445-3327 for assistance with the disposal of pure peroxides.
- Peroxide-Forming Chemicals
Many chemicals can auto-oxidize to form explosive peroxides (see Common Peroxidizable Chemicals on the UNR EH&S Website under Chemical Hygiene). Peroxidation can occur in the following types of compounds: I) aldehydes, II) ethers, III) compounds with vinyl, allylic or benzylic hydrogens, and IV) compounds containing a tertiary C-H group. Generally, increased volatility of the parent chemical increases the likelihood that dangerous levels of peroxides will form, since evaporation leads to concentration of the peroxide product.- Follow storage recommendations in section 10.3 for peroxide-forming chemicals.
- Alwaystest peroxide-forming chemicals for peroxides prior to distillation or other heating operations.Never distillpotential peroxide-forming chemicals to dryness. Always leave 10% of the original liquid volume. Note: Some manufacturers add peroxide inhibitors to some peroxide-forming chemicals. Since distilling removes the inhibitor, distilled chemicals should be used immediately or new inhibitor must be added.
- After each use, carefully wipe the container neck, cap, and threads with a cloth before resealing.
- Immediately set aside andDO NOT USEany peroxide-forming chemical if a precipitate, crusty residue or oily viscous layer is present. Contact your lab supervisor or EH&S for immediate assistance.
- Reactive chemicals are those that have the potential to vigorously polymerize, condense,
or become self-reactive due to shock, pressure, temperature, light, or contact with
another material. Examples of reactive chemicals are explosives, peroxides, water-reactives,
and pyrophorics.
- Corrosive and Contact-Hazard Chemicals
- Avoid skin contact with chemicals considered to be corrosive or a skin sensitizer.
- When possible, use mechanical means to handle or transfer these chemicals.
- Use gloves and other personal protective clothing (lab apron or coat) known to be resistant to permeation and degradation by the chemical.
- Check gloves and protective clothing for holes.
- Wear safety goggles (with indirect venting) as a minimum when handling these chemicals. Wear a face shield in addition to goggles when there is a reasonable possibility of splashing.
- Hydrofluoric acid is highly corrosive to body tissue, even in dilute solutions. Personnel using hydrofluoric acid must be specifically trained prior to use. Always seek immediate medical attention if skin or eye contact occurs.
- Avoid skin contact with chemicals considered to be corrosive or a skin sensitizer.
- Cryogenic Liquids
Cryogenic liquids undergo large volume expansion upon transition to the gas phase. Under the right conditions, cryogenic liquids are capable of condensing atmospheric oxygen, resulting in an oxygen-enriched environment. An oxygen-enriched environment in combination with flammable/combustible materials and an ignition source can result in explosion. Hazards of cryogenic liquids include fire, explosion, pressure buildup, as well as severe frostbite (on contact with skin) and asphyxiation.- Always wear appropriate personal protective equipment to prevent skin and eye contact. Heavy gloves (special cryogenic gloves are available), safety glasses and face shield, and lab apron are recommended.
- Handle objects that are in contact with cryogenic liquids with tongs or proper gloves.
- Keep liquid oxygen away from organic materials and ignition sources.
- Only work with cryogenic liquids in well-ventilated areas to avoid localized oxygen depletion or build up of flammable or toxic gas.
- Transfers or pouring of cryogenic liquids should be done carefully to avoid splashing.
- Cryogenic liquid/dry ice baths should be open to the atmosphere to avoid pressure build up.
- Transfer of liquid hydrogen in an air atmosphere can condense oxygen in the liquid hydrogen, creating an explosion risk.
- Compressed Gases
Compressed gases are considered more hazardous to handle than liquids or solids because of the high pressure involved and ability to spread rapidly when released. Additionally, many compressed gases are flammable, toxic and corrosive.- Check connections and hoses regularly for leaks using soapy water or 50% glycerin-water solution. When utilizing highly flammable or toxic gas, check the system using inert gas prior to introducing the hazardous gas.
- Secure cylinders upright by chain, rack or other approved means.
- Compressed gas cylinders must be transported using hand-trucks or other appropriate
means. NEVER TRANSPORT UNSECURED COMPRESSED GAS CYLINDERS!
- Cylinders should be transported upright whenever possible (always transport acetylene in an upright (vertical) position).
- When using compressed acetylene, do not: (I) exceed a working pressure of 15 psig, and (II) do not use vessels, piping, or other materials that contain more than 50% copper.
- Replace valve caps when cylinders are not in use.
- Remove damaged or defective cylinders from service (contact the cylinder vendor for assistance).
Section 7: Control Measures
- There are three general methods used to control chemical hazards: engineering controls,
administrative controls, and personal protective equipment. Chemical hazards are to
be controlled using these controls in the following order of preference:
- Engineering Controls such as substituting a less toxic chemical for one that is more toxic, laboratory ventilation hoods, containment enclosures, and facility design.
- Administrative Controls such as written safety procedures, training, controlling access to hazardous areas, and work practices including personal hygiene and laboratory technique.
- Personal Protective Equipment such as respirators, gloves, and chemical protective clothing.
- Engineering controls are the preferred method since the hazard is controlled at the source with minimal continued human intervention (it is part of the system). Personal protective equipment is the least desirable method since it does not directly reduce the hazard, its failure results in direct exposure to the hazard, and its effectiveness depends directly on proper human implementation. Administrative controls and personal protective equipment are used to enhance engineering controls and when engineering controls are not feasible.
- Criteria for Determination and Implementation of Control Measures
- Implementation of the above controls is required whenever there is a reasonable possibility of exceeding an occupational exposure limit (either the OSHA PEL or the ACGIH TLV, whichever is most conservative).
- Implementation of controls is to be considered for all laboratory operations involving hazardous chemicals in order to minimize chemical exposure to laboratory personnel.
- Use of Laboratory Hoods
General laboratory ventilation is not sufficient to prevent accumulation of chemical vapors; therefore, laboratory hoods are the primary control used to protect workers from chemical exposure. Laboratory hoods should be used whenever possible to minimize personnel exposure to airborne chemicals.- Verify sufficient inward airflow before using a hood.
- A strip of lightweight paper (such as a Kimwipe) should be readily pulled inward when held at the face of the hood.
- Use perchloric acidonlyin hoods designed for perchloric acid use. Such hoods contain water spray systems
to wash down the interior of the hood, ducting, fan, and stack to prevent accumulation
of explosive perchlorate crystalline material.
- Turn on the water spray system whenever perchloric acid is being heated in the hood or is otherwise volatilized.
- When possible, positions the hood sash such that the glass is between the worker (especially the face) and the chemical source. Close the hood sash when not working in the hood.
- Avoid rapid movements at the face of the hood, as they tend to create competing air currents and reduce the ability of the hood to contain air contaminants.
- Keep chemical sources and apparatus at least six inches behind the face of the hood.
- Minimize equipment placed in the hood to avoid dead air spaces and/or eddies. o Equipment placed in hoods should be placed on blocks to allow air to flow around the equipment.
- EH&S performs laboratory hood performance evaluations on an annual basis.
- A face velocity of 80-120 fpm is recommended for most laboratory hoods. A face velocity outside of this recommended range may be approved for specific use by EH&S.
- Laboratory hood performance should also be evaluated following any maintenance, repair, or modification that could affect ventilation performance.
- Consult with EH&S and Facilities before making any change to a ventilation system (laboratory hood or general room ventilation) or for assistance with unique experimental set-ups.
- Do not use lab hoods to dispose of chemicals by evaporation unless the vapors are trapped and recovered for proper waste disposal.
- In the event of a hood failure during chemical use:
- Turn off power to apparatus in the hood.
- Stabilize the chemical source as much as possible to minimize release.
- Close hood sash.
- Notify other occupants of the laboratory.
- Notify the laboratory supervisor and/or the department office and call Buildings and Grounds to report the problem.
- If hazardous chemicals are released from the hood in sufficient quantity as to present a fire or health hazard, evacuate the area and contact your lab supervisor and EH&S or 9-911.
- If you must evacuate the building pull a fire alarm pull station.
- Verify sufficient inward airflow before using a hood.
- Prior Approval of Operations
- Laboratory personnel must receive prior approval from the laboratory supervisor before
proceeding with a task involving hazardous chemicals under the following circumstances:
- When performing a new laboratory procedure that is substantially different from procedures already in use.
- When working with particularly hazardous substances.
- It is likely that the action level for a hazardous chemical could be exceeded, or there are other hazards with high potential for personal harm (such as explosion).
- There is a procedural change that significantly increases the overall hazard of the procedure.
- Laboratory personnel suspect that they or others have been exposed to hazardous chemicals resulting in illness or symptoms of exposure, or otherwise suspect a failure of any safeguards. When conducting unattended operations involving hazardous chemicals.
- When appropriate, the principal investigator or laboratory supervisor can give ongoing approval for similar operations that are of a comparable hazard level. For example, prior approval of a set of experiments that are similar in nature and hazard level would constitute prior approval of each individual experiment (that is, prior approval of each individual experiment is not required).
- Documentation of the Lab Supervisors prior approval should be maintained. This documentation should outline the work to be performed and be signed by the Lab Supervisor. This can be documented using a dedicated prior approval form or an entry in a research notebook.
- Laboratory personnel must receive prior approval from the laboratory supervisor before
proceeding with a task involving hazardous chemicals under the following circumstances:
- Laboratory Entrance Signs
- The entrance to each laboratory or chemical storage area must be posted with the name and phone numbers of the laboratory supervisor, and other designated personnel who can be contacted in case of an emergency. Phone numbers that will enable designated personnel to be contacted during off-hours should be included. Entrance signs should also indicate the presence of any specific hazards (such as carcinogens or OSHA regulated chemicals).
- Personal Protective Equipment
Personal protective equipment is effective only when used properly and when in proper working condition. Always inspect all personal protective equipment before using. Do not use defective protective equipment.- Eye Protection
- Eye protection must be worn at all times in the laboratory. All eye protection must
meet American National Standards Institute (ANSI) code Z87.1 (Z87 will be imprinted
or labeled on the eyewear).
- Chemical splash goggles with indirect venting should be worn when there is reasonable potential for chemical splash.
- Wear a face shield when working with highly corrosive chemicals (such as strong acids and bases), when there is reasonable potential for explosion or implosion, or whenever the splash potential warrants it. Goggles must be worn under the face shield (safety glasses can be worn if and only if goggles will not fit under the face shield).
- The wearing of contact lenses while performing chemical operations is a controversial
issue. Contact lenses can be worn by laboratory workers under the following circumstances:
- The laboratory supervisor is notified and approves the wearing of contact lenses in his or her laboratory.
- Protective eyewear that is appropriate for the hazard is worn. Contact lenses do not provide adequate protection and are not considered protective equipment. Contact lenses should not be worn because they can seriously complicate the flushing of the eyes.
- WNC has no funds to provide prescription glasses for students who own only contact lenses. Students may not be removed from the lab for lacking financial means to procure prescription glasses. Students are to be advised (and sign off acknowledging the advisement) that wearing glasses in the lab is to their health advantage.
- Eye protection must be worn at all times in the laboratory. All eye protection must
meet American National Standards Institute (ANSI) code Z87.1 (Z87 will be imprinted
or labeled on the eyewear).
- Hand Protection
- When working with hazardous chemicals, wear gloves made of material known to be resistant
to permeation by the chemical. NO ONE GLOVE MATERIAL IS RESISTANT TO PERMEATION BY
ALL CHEMICALS.
- Consult the MSDS, chemical manufacturer, or EH&S for information on appropriate gloves.
- See the Glove Selection Guidelines on the UNR EH&S Website under Chemical Hygiene.
- Inspect gloves prior to use. Discard gloves if there are signs of degradation, tears, punctures, or swelling. Test gloves for the presence of leaks by inflating the glove with air (do not inflate by mouth).
- Remove gloves when leaving a chemical use area. Do not spread chemical contamination by handling common items such as books, phones, and doorknobs.
- Routinely diluted acids and bases for instructional utilization do not require the wearing of gloves (refer to the MSDS/SDS for specific requirements).
- When working with hazardous chemicals, wear gloves made of material known to be resistant
to permeation by the chemical. NO ONE GLOVE MATERIAL IS RESISTANT TO PERMEATION BY
ALL CHEMICALS.
- Body Protection
- Always wear a fully buttoned lab coat when handling chemicals.
- A rubberized laboratory apron or other specialized body protection should be worn when there is real potential for chemical splash.
- Foot Protection
- Sandals, open-toed shoes, open-heeled shoes, basket-weave styles and clogs are not allowed in the lab. Wear tennis shoes or the like that will provide continuous, wrap-around coverage of your feet. Students may be removed from the lab for wearing improper foot wear; if students live close enough, s/he may return to complete the experiment for the day; otherwise, its a 0 for the day.
- Respiratory Protection
- Respiratory protection is not normally required during laboratory operations if the work is performed in a properly functioning laboratory hood. Operations involving highly volatile chemicals, large volumes of chemicals, chemicals with low exposure limits (such as less than 10 pm), or operations that cannot be performed in a hood, may require the use of respiratory protection. All respiratory protection must be approved prior to use by EH&S. All personnel must be fitted and trained for respirator use by EH&S prior to using respiratory protection. Contact the EH&S Coordinator at 445-3327 regarding respirator use and approval.
- Eyewash Fountains and Safety Showers
- All laboratories and chemical storage areas must be equipped with eyewashes and safety showers. They must be easily accessible from any point in the laboratory by a person with chemical splashed in their eyes or on their body.
- Eyewash fountains and safety showers will be run monthly to reduce the threat of microbial infection (a minimum activation time of 3 minutes recommended).This shall be coordinated by EH&S, the Division and Facilities to minimize classroom disruption. Facilities will be notified to have personnel available for the clean up operations.
- Eyewash fountains and safety showers are to be kept clean and in good working condition. A flow rate of 30 gallons of potable water per minute for showers and 0.4 gallons of tempered, potable water per minute for fountains is recommended (see ANSI Z358.1).
- Lab workers must be trained in the location and use of eyewash fountains and safety showers.
- Eye Protection
Section 8: Exposure Monitoring
- EH&S is responsible for performing exposure monitoring of laboratory operations. Contact the WNC EH&S CHO to request air monitoring in your work area.
- To ensure that personnel exposures do not exceed exposure limits, air monitoring is
to be performed whenever there is reason to believe that airborne chemical concentrations
exceed the action level. The action level is considered to be the OSHA-defined action
level (generally one-half the PEL) or one-half the ACGIH TLV (or other exposure limit
being used), whichever is more conservative.
- Note: Operations involving highly volatile chemicals, large volumes of chemicals, chemicals with low exposure limits (such as less than 10 ppm), or operations that cannot be performed in a hood, are the most likely to exceed the action level.
- Workers should be familiar with the odor and/or visual characteristics of the chemicals they work with, as these characteristics can sometimes be used to detect the presence of chemicals in the laboratory.Do not use chemical odor and/or visual characteristics as a means of determining that inhalation exposure limits are not being exceeded, as sometimes these characteristics are only detected at concentrations far above that which is considered safe. For example, the odor threshold (the concentration at which a chemical can be detected by its odor) of acetonitrile is 1160 ppm, while the exposure limit is 40 ppm!
- Notify your supervisor whenever there is reason to suspect that a chemical exposure limit might be exceeded, whether or not a suspicious odor is noticed.
Section 9: Hazard Communications
- Chemical Labeling
Unidentified chemicals represent an increased hazard to personnel due to lack of information on how to properly handle the material. Additionally, unknown chemicals are a large financial burden since they cannot be disposed of without first performing laboratory analysis. To avoid unidentified chemicals, label all chemical containers as described below.- General Labeling Requirements
- Labels on incoming containers must not be defaced or removed.
- Labels must be legible (in English), and contain the following information: (i) identity of the chemical, (ii) appropriate hazard warnings, and (iii) name and address of the manufacturer, importer, or other responsible party. Globally Harmonized chemical labeling requirements must be used for all chemicals to provide consistency with the products Safety Data Sheet Pictograms and signal words are required.
- When labels are not complete, or the MSDS/SDS is not available in the lab, the chemical is not to be used.
- Chemicals that are transferred from their original container to a secondary storage
container must be labeled with the chemical name and appropriate hazard warnings (contact
the laboratory supervisor if assistance is needed in labeling small containers). The
chemical name and hazard warning and other globally harmonized items, must be consistent
with the original label.
- The hazard warning is a brief statement of the hazardous effects of the chemical (such as flammable or causes lung damage); other precautionary information (such as do not use near open flame) may be included but is not required.
- Temporary chemical containers (such as beakers and volumetric flasks) used during laboratory projects need only a content identifier label. This provided that such containers are in the control of an individual until the chemical is removed and the container properly rinsed.
- Chemicals that have been diluted or mixed with other chemicals for use as laboratory reagents (such as buffers, dilute acid or base solutions, or indicators) need only a content identifier label. Include chemical concentrations on containers of dilute and bases, and other reagents as appropriate. o It is prudent to include hazard warnings for reagents that are highly toxic, highly flammable or carcinogenic.
- Chemicals developed in the laboratory, whose identity is known and which have been determined to be hazardous, must be labeled with the chemical name and appropriate hazard warnings and other globally harmonized requirements.
- If a chemical substance is prepared for another user outside of the laboratory, the requirements of the OSHA Hazard Communication Standard (29 CFR 1910.1200) must be met, including preparation of a Material Safety Data Sheet or Safety Data Sheet (MSDS/SDS).
- Label all permanent piping of laboratory gases with a content identifier label.
- Labels on incoming containers must not be defaced or removed.
- Labeling Research Materials
The hazards of research materials are usually not completely known; therefore complete hazard labeling is not possible. Nevertheless, research materials must be labeled as completely as possible using the following guidelines:- Label all containers of research materials with the name of the responsible researcher
and as much information as is available with respect to identity and hazards.
- References to research notebooks, etc. should be included when necessary to convey identity and hazard information.
- Label all containers of research materials with the name of the responsible researcher
and as much information as is available with respect to identity and hazards.
- General Labeling Requirements
- Material Safety Data Sheets and Safety Data Sheets
- All Material Safety Data Sheets and Safety Data Sheets (MSDS/SDS) received with incoming hazardous chemicals must be retained.
- MSDS/SDS for each hazardous chemical received from outside the laboratory must be
readily available (hardcopy or electronic) to laboratory workers. If an appropriate
MSDS/SDS is not readily available, the chemical must not be used.
- MSDS/SDS is not required for uncharacterized research material used only by the laboratory that produced it, or for laboratory reagents mixed in the laboratory.
- Laboratory personnel can access MSDS/SDS via computers. There are many sites: often
the manufacturers site is the easiest to access and most informative.
- Log on to the Internet.
- Type in http://www.ehs.unr.edu.
- Click on Material Safety Data or Safety Data Information.
- Click on one of the MSDS/SDS sites listed.
- Follow the menu to access the MSDS/SDS for the chemical.
- Note: Any computer with Internet access can be used to access MSDS/SDS.
- Global Harmonization
- OSHA is changing Hazardous Communication requirements. These changes include:
- Safety Data Sheets (SDSs) with sixteen sections
- New hazard classes
- New pictograms
- Required training
- OSHA is changing Hazardous Communication requirements. These changes include:
Section 10: Chemical Storage
The primary storage concerns with all chemical materials are to minimize the amounts stored, to avoid contact between incompatible chemicals, and to ensure that hazardous storage conditions (for example, light and heat) are not present. Provide adequate security so that unauthorized personnel do not have access to chemicals.
- General Storage Recommendations
Chemical containers should be labeled with the date of receipt and the date opened.- A chemical inventory must be maintained for all chemicals routinely stored in the
laboratory.
- At a minimum, the inventory should include the chemical name, quantity, and storage location.
- The inventory must be kept current.
- The inventory should be verified through periodic physical inventory and inspection. Chemicals with any of the following conditions should be disposed of through EH&S: I) shelf life has been exceeded, II) evidence of chemical reaction, III) no label or unreliable label, IV) container and/or cap corroded, leaking, or otherwise in poor condition.
- Keep chemical storage areas well ventilated and away from heat or direct sunlight.
- Store liquid chemicals in secondary containment (such as cabinets, trays and tubs) with sufficient volume to contain spills.
- Storage cabinets and shelving should be sturdy and secured to the wall. Shelves should be fitted with a lip or barrier at least two inches high to prevent chemicals from falling off the shelves.
- Unwanted chemicals whose continued storage and use do not present a safety hazard should be given to other labs for use whenever possible. Otherwise, dispose of unwanted chemicals through your lab supervisor who will contact EH&S.
- Store corrosive chemicals, highly toxic chemicals, and large chemical containers below eye level.
- A chemical inventory must be maintained for all chemicals routinely stored in the
laboratory.
- Chemical Hazard and Compatibility
- Segregate chemicals according to their hazard classification and compatibility. Separate
incompatible chemicals within each hazard class. A recommended chemical storage scheme
based on general hazard classifications is as follows:
- General Chemical Storage
- Acids
- Bases
- Flammable/Combustible Liquids
- Oxidizers
- Highly Reactive
- Compressed Gases
- Note: See UNR EH&S Website under Chemical Hygiene for the Partial List of Chemical Incompatibilities.
- Separate solid chemicals from liquid chemicals.
- When a chemical fits in more than one hazard category, store the chemical using the most severe (or likely to occur) hazard for storage criteria. Fire is generally considered to be the most severe hazard; therefore use flammability/combustibility as the major storage criteria.
- Store highly toxic chemicals (particularly hazardous chemicals) in individual plastic bags or other unbreakable secondary containment (either trays or a second closed container). Provide security to limit access to authorized users.
- General Chemical Storage
- General chemical storage includes all solid chemicals not designated to another specific hazard group. Store these chemicals using only general storage recommendations. Separate chemicals into organic and inorganic sections.
- Acids
- Store oxidizing acids (such as nitric acid, perchloric, and chromic acid) away from organic acids and flammables. Store perchloric acid away from combustible materials (such as wooden shelves and paper).
- Store inorganic acids separately from organic acids.
- Concentrated acids should be stored in an approved acid storage cabinet.
- Separate acids from active metals (such as sodium, magnesium, and potassium) and chemicals that can generate toxic gases on contact (such as inorganic cyanides and sulfides).
- Store solid form acids with the general chemicals.
- Bases
- Store solid form bases with the general chemicals.
- Flammable and Combustible Liquids
- Containers for flammable and combustible liquids must meet the maximum container requirements
listed in 29 CFR 1910.106 (d) (2) (III).
- The exception is when the flammable liquid is in the original container and high purity must be maintained.
- When possible, store quantities of flammable liquids greater than one liter in safety
cans.
- When using safety cans: I) never disable the spring-loaded closure and II) keep flame arrestor screens in place and replace screen if punctured or damaged.
- A maximum of 25 gallons of Class I liquids per laboratory can be stored in safety cans outside of a flammable storage cabinet.
- When possible, store all flammable and combustible liquids in approved fire resistant flammable liquid storage cabinets.
- Maximum storage volumes of flammable and combustible liquids (including waste material)
outside of approved flammable storage cabinets or safety cans are:
- 2 gallons of flammable liquid (Class I) per 100 ft2 of laboratory space, up to a maximum of 15 gallons per laboratory.
- 4 gallons of Class I, II and III liquids combined per 100 ft2 of laboratory space.
- When Class I liquids are combined with Class II and III liquids, the quantity of Class
I liquids must not exceed the maximum quantity permitted for Class I liquids alone
(i.e., maximum of 15 gallons of Class I liquids per laboratory).
Note: Maximum quantities of flammable and combustible liquids in teaching laboratories are one-half of the above volumes.
- Do not use a domestic refrigerator for storage of flammable liquids. Use an approved
explosion safe or explosion proof refrigerator for refrigerated storage of flammable
liquids.
- The quantity of flammable liquid stored in a refrigerator is included in the maximum amount that can be stored outside of an approved cabinet.
- Do not store more than 60 gallons of flammable and combustible liquids combined, in
a flammable/combustible storage cabinet.
- Do not remove vent bungs from storage cabinets.
- Storage cabinets must be labeled Flammable-Keep Fire Away.
- Quantities of Class I flammable liquids greater than 60 gallons must be stored in an approved indoor storage room.
- Flammable storage areas should be clearly marked with appropriate signs.
- Containers for flammable and combustible liquids must meet the maximum container requirements
listed in 29 CFR 1910.106 (d) (2) (III).
- Oxidizers
- Separate oxidizers from flammable and combustible materials, and reducing agents.
- Highly Reactive
- Store water reactive chemicals in a secondary container or other protective barrier against accidental exposure to water. Do not store under sinks or near other locations with potential water exposure.
- Store pyrophoric chemicals in accordance with the manufacturers (MSDS) recommendations, and away from flammable chemicals, and heat sources.
- Compressed Gases
- Segregate and clearly mark full and empty cylinders.
- Segregate according to hazard class and chemical compatibility.
- Empty cylinders should be labeled and stored separately.
- Store compressed gas cylinders away from heat sources, and flammable and highly combustible materials (such as oil and greases).
- Segregate flammable and oxidizing gases.
- Store flammable gases away from flammable solvents, combustible material, ignition sources (including unprotected electrical connections), and oxygen gas cylinders and liquid oxygen (at least 20 feet).
- Store flammable and highly toxic gases in well-ventilated areas.
- Segregate and clearly mark full and empty cylinders.
- Segregate chemicals according to their hazard classification and compatibility. Separate
incompatible chemicals within each hazard class. A recommended chemical storage scheme
based on general hazard classifications is as follows:
- Cryogenic Liquids
- Store cryogenic liquids in containers designed for the pressure and temperature to which they will be subjected. Double-walled, evacuated Dewar flasks are commonly used.
- Containers and systems containing cryogenic liquids should have pressure relief mechanisms.
- Cryogenic liquid cylinders and other containers (such as Dewar flasks) should be filled no more than 80% of capacity to protect against thermal expansion.
- Dewar flasks should be shielded with cloth tape or wire mesh to minimize flying glass and fragments should an implosion occur.
- Peroxide-Forming Chemicals
Appendix IV contains a list of chemicals known to form peroxides during storage. Peroxide-forming chemicals are to be stored and tested as described in this section in order to minimize incidents resulting from formation of peroxides during storage. Additionally, organic peroxide-forming chemicals are highly flammable and must be stored as such.- Maintain an inventory of peroxide-forming chemicals present in each laboratory and
review the inventory at least every twelve months (three months if chemicals on List)
- See the UNR EH&S Website under Chemical Hygiene for the list of Common Peroxidizable Chemicals.
- Label all containers with date received, date opened, peroxide test date(s), and test results.
- Test all peroxide-forming chemicals for accumulation of peroxides every twelve months
after opening, until consumed or disposed of as waste. Highly volatile chemicals or
chemicals that are opened frequently should be tested more often.
- The administrative control limit for peroxides is 100 ppm; chemicals with a peroxide content greater than 100 ppm should be disposed of, or decontaminated.
- The safe storage period for unopened chemicals from the manufacturer is 18 months. Unopened containers older than 18 months should be assumed to contain peroxides until tested.
- Store peroxide-forming chemicals in airtight bottles to minimize evaporation and the introduction of oxygen (a blanket of nitrogen gas can be used).
- Storing ether in refrigerators is not permitted unless the refrigerator is approved
for flammable storage. Refrigeration does not prevent peroxide formation!
- Peroxide-forming chemicals should not be stored at or lower than the temperature at which the peroxide freezes or precipitates since peroxides in these forms are extremely sensitive to shock and heat.
- Minimize the inventory of peroxide-forming chemicals in the laboratory. Do not purchase large containers of peroxide-formers if the quantity exceeds actual needs within the three or twelve month expiration period.
- Immediately dispose of rusted, damaged, or suspicious-appearing containers of peroxide-forming chemicals.
- Maintain an inventory of peroxide-forming chemicals present in each laboratory and
review the inventory at least every twelve months (three months if chemicals on List)
Date(s) Revised | February 3, 2015; June 20, 2013; October 30, 2012; September 2, 2008; October 10, 2005; | Date(s) Reviewed |
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