HAZARD CONTROLS

This section discusses control procedures for limiting employee exposure to chemical hazards.

Standard Operating Procedures

Standard Operating Procedures for all chemicals at LBNL are to minimize employee exposure to hazards by utilizing chemical substitution, engineering controls, administrative controls, personal protective equipment, work practice controls, and emergency procedures.  These controls and procedures are described in this section.   All employees are required to wear eye protection, lab coats and chemically resistant gloves when handling hazardous chemicals.  Operations that may generate airborne gases, vapors, dusts, fumes, and smoke shall be done in a fume hood or glovebox.  In addition, specific controls for the following classes of hazardous materials are described in more detail:

• Acids/Bases
• Particularly Hazardous Substances
• Flammable and Combustible Liquids
• Laser Dyes
• Peroxide-Forming Chemicals
• Water-Reactive Chemicals
• Engineered Nanomaterials

Work Leads shall incorporate the controls discussed in this section into Job Hazard Analyses and Activity Hazard Documents.

Chemical Use, Selection, and Substitution

Before a chemical or a product is introduced or used in a workplace, the Work Lead shall:

• Review the hazards of the material and assess the conditions under which it will be used.  This information may be obtained from the MSDS or by consultation with EH&S Industrial Hygienists.
• Determine if the chemical can be substituted with a safer chemical alternative. An EH&S Industrial Hygienist can be consulted to provide assistance to identify substitute chemicals.
• Determine if the chemical can be borrowed from someone within the research group or the Division. If the chemical must be purchased, keep working quantities of all hazardous materials to a minimum.  Procure, use, and store the minimum amount of material required.
• Determine if the chemical is a restricted item.  If it is, then EH&S Division notification or approval  must be obtained in accordance with the Laboratory's procurement requirements.

NOTE:  When a chemical is synthesized or produced at LBNL and is to be used by someone outside the laboratory or research group where it was produced, an MSDS and warning label shall be generated.  See MSDSs for additional requirements.  If the chemical is to be used in the laboratory, the Work Lead shall conduct a hazard assessment, identify the hazards, establish controls, label the container,and provide training to the users.

Selection and Use of Engineering Controls

Engineering controls include local exhaust ventilation systems, laboratory fume hoods, enclosures and shields.  Except for substitution, these provide the most effective means of control because they enclose the hazard or physically separate it from the employee.

Local Exhaust Ventilation, Fume Hoods

Local exhaust ventilation and laboratory fume hoods are used to remove airborne contaminants from an employee's breathing zone. Self-contained (ductless) hoods that recirculate air back into the workspace are not an acceptable means to control airborne chemicals. LBNL policy on selecting, installing, using, and testing ventilation systems is provided in PUB-3000, Chapter 4, “Industrial Hygiene.”  The selection, procurement, installation, and balancing of all ventilation systems must be done through Facilities. 

Local exhaust ventilation (such as laboratory fume hoods, gloveboxes, “snorkels” or industrial ventilation) is required when handling chemicals in a manner that can produce an airborne hazard. 

Examples include but are not limited to:

• Using reactive metals or pyrophoric materials,
• Using particularly hazardous substances (i.e., acutely toxic, carcinogenic or reproductive toxins),
• Handling volatile toxic liquids,
• Using organic liquids or solvents,
• Conducting procedures that generate airborne particulates (e.g., dust) or liquid aerosols of even moderately toxic chemicals,
• Using odiferous compounds,
• Synthesizing or reacting chemicals,
• Diluting concentrated acids and bases.  NOTE:  Operations involving heating or evaporating perchloric acid must be evaluated by an EH&S Industrial Hygienist to determine if special controls (such as using an acid fume hood with wash-down systems to prevent the accumulation of explosive perchlorate crystals) are needed,
• Discharging gases/vapors from vacuum pumps and distillation columns,
• Discharging harmful gases and vapors from drying ovens and muffle furnaces.  NOTE: Consult an Industrial Hygienist to help make this determination. 

Fume hoods, gas cabinets, and other ventilated enclosures may be equipped with electronic flow sensors or pressure gauges. If the flow sensor alarm goes off (red light, warning sound) or the pressure falls below the indicated set point on the pressure gauge, discontinue work in that system and call the Work Request Center (ext. 6974) to report the condition. Do not simply mute the alarm and continue working—the alarm indicates that something is not operating correctly. If the system is restored and the alarm resets, you may resume work, but you should report the condition so that the cause may be investigated.

Gloveboxes and Gas Cabinets

• Gloveboxes that provide a nonreactive atmosphere are required for operations involving alkali metals and pyrophoric materials.
• Gas cabinets are required for health hazard and pyrophoric gases as described in PUB-3000, Chapter 13, “Gases.”   NOTE: Fume hoods may be used for this purpose as well, based upon Industrial Hygiene review and concurrence.

Chemical Storage Cabinets

• New chemical storage cabinets (such as storage lockers for flammable liquids) must be connected to the building’s exhaust system. This applies to all cabinets installed during renovation or new construction.  Most chemical storage cabinets are equipped with two bungs.  It is LBNL policy to connect the bottom bung to the exhaust system with a metallic pipe (copper or steel flex hose of 2-inch diameter).  The top bung must be connected to a source of non-laboratory supply air and must be fitted with a flame arrester.
• Existing cabinets showing signs of interior corrosion or whose contents produce strong odors during storage shall also be ventilated

Laboratory Room Exhaust

• Laboratory heating, ventilating, and air conditioning (HVAC) systems must provide 100% outside air to laboratory spaces (no recirculation of air is allowed). The HVAC systems are balanced to keep laboratory spaces at a negative pressure relative to adjacent offices and hallways. This ensures that vapors, gases, fumes, and particulates do not migrate to non-laboratory spaces.  A minimum ventilation rate of 1 cubic feet per minute of exhaust per square foot of laboratory area is required.  Exceptions to maintaining negative pressure in a laboratory provided that it can be demonstrated that research is adversely affected by ambient air drawn into the workspace and that EH&S Industrial Hygienist concurrence is given.  

Ventilation System Performance Evaluations

• Facilities is responsible for installing, balancing and function testing all ventilation devices.
• EH&S Industrial Hygienists perform periodic testing of fume hoods, gas cabinets, gloveboxes, canopy hoods and snorkels. These are evaluated initially after installation. Ventilation devices with no visual/audible read-out/alarm for the air flow are also tested annually.  Those equipped with visual/audible read-out/alarms for airflow are evaluated every other year. Ventilation devices used for radiological work are evaluated annually.
• Ventilation system performance must be checked whenever the system has been modified, such as by adding new hoods or relocating or replacing system components (including hoods).

Safety Shields

• Safety shields must be used for protection against possible explosions or uncontrolled reactions.  Laboratory equipment must be shielded on all sides to ensure there is no line-of-sight exposure of personnel.

Personal Protective Equipment

Personal protective equipment (PPE) is to be used as a supplement to but not as a substitute for engineering controls.  PPE includes chemically resistant gloves, eye wear, footwear, coveralls and respiratory protection.  PPE may be used as a sole means of control if the use of other controls is not feasible.  PPE is provided at no personal expense to the individual. To be effective, employees must understand the uses and limitations of PPE. 

For additional information on Berkeley Lab's policies on PPE, see PUB-3000, Chapter 19.

The following general requirements apply to selecting and using PPE:

• Skin and eye contact shall be prevented. PPE must be selected on the basis of the hazards present, the type of materials used, and the manner in which they will be handled. Work Leads are responsible for ensuring that a Job Hazard Analyses is performed prior to selecting PPE and for ensuring that employees use PPE properly.
• Employees must be trained in the uses and limitations of PPE. This is the Work Lead's responsibility. An Industrial Hygienist may be consulted to provide guidance on the selection and use of PPE and to assist in training.
• Employees must report problems (such as deterioration and degradation) to Work Leads immediately.

Minimum PPE Requirements for Laboratory Activities:

• Employees must wear at a minimum, laboratory coats, safety glasses with side shields, closed toe footwear, and chemically resistant gloves. 
• Some areas in labs may not require PPE.  These shall be clearly demarcated by the Line Manager with black and yellow tape.
• Open-toed shoes and sandals are not permitted.
• Remove all PPE including gloves prior to leaving the work area, and before touching door knobs and using the phone to prevent the spread of chemical contamination.
• Disposing of PPE
• Normally, disposable PPE used in laboratory settings (such as gloves, Tyvek coveralls, and booties) may be disposed of as regular trash. However, PPE used for protection against such materials as engineered nanomaterials, lead and asbestos, special disposal procedures must be disposed of as hazardous waste. Consult with a Waste Generator Assistant for more information.
• Also consult with a Radiological Control Technician for disposing of PPE used in radiological areas.

Gloves

• Gloves must be worn when using hazardous chemicals, when handling materials at temperature extremes or when handling materials with sharp or rough surfaces. It is especially important to wear gloves when handling chemicals that can be absorbed through the intact skin..  Consult MSDSs and the following Web site to identify chemicals that have this property.  This may not be a complete list, therefore contact an EH&S Industrial Hygienist if you have any questions about a particular compound: www.osha.gov/web/dep/chemicaldata/#target.
• Always remove gloves before touching common use items such as phones, door knobs and computers. This will prevent contamination of unprotected individuals.

Glove Selection

• Chemically resistant gloves are manufactured from a variety of materials, including nitrile, polyvinyl chloride, natural rubber (latex), and Viton. No single glove material provides universal protection against all chemical agents. Therefore, gloves must be selected on the basis of their resistance to the material(s) being handled, their suitability for the procedures being conducted, and their resistance to wear as well as temperature extremes. Improper selection may degrade the gloves, allow the chemical to permeate through the gloves, and ultimately expose the wearer to the chemical.  This is a potentially serious situation.  Use chemical resistance charts and glove selection databases (below) to choose gloves.
• In addition to the specific chemical(s), other factors to consider in selecting gloves are how and where they will be used.  In shop environments, gloves may be subjected to rougher handling and may be totally immersed in chemicals such as cleaners and degreasers.  However, in labs, manual dexterity may be an issue, and splashes, as opposed to total immersion in the chemical, are more common.  Gloves used in shop settings are thus required to be more resistant to tears and abrasion than those used in laboratory environments and are normally thicker (greater than 10-15 mils).  In laboratories, thin, lightweight gloves are generally preferred (less than 10 mils).  As a point of reference, typical dishwashing gloves are approximately 15 to 20 mils thick, and surgical latex gloves are on the order of 3 to 8 mils thick. 
• A final consideration in glove selection is an individual’s sensitivity to the materials and chemicals used in the manufacture of gloves.  Some people have allergic reactions to natural rubber proteins in latex, glove powder (used for absorbing perspiration), or other chemical constituents, such as rubber accelerators (carbamates, thiurams, and mercaptobenzothiazole).

Chemical Resistance Charts and Glove Selection Databases

• Objective data (such as chemical resistance charts and selection databases) must be used to choose the appropriate glove.  Chemical resistance charts are available from the Laboratory’s Chemical Hygiene and Safety Program Manager (ext. 5286) or directly from the manufacturer.
• The web sites listed below are recommended for selecting chemically resistant gloves.  Some allow different ways to search for the most appropriate glove.  Searching by chemical name will produce a list of gloves that protect against a particular agent.  Searching by glove type will give a list of chemicals for which a specific glove was tested.  Glove thickness is normally listed or is available by clicking on the link for the recommended glove. 
  • Glove Manufacturer Web Sites:
    • SpecWare Online Chemical Hand Protection
    • ChemRest Guide to Chemical Resistant Best Gloves
    • MAPA Chemical Resistance Guide
  • Independent Glove Selection Web Sites:
    • Michigan State University Chemical-Resistant Glove Guide
    • Oklahoma State University Chemical Guide and Permeation Tables
• An EH&S Industrial Hygienist may also be contacted for assistance in glove selection.

Eye and Face Protection

This section discusses the uses and limitations of safety glasses, chemical goggles, and face shields. The type of protection selected must be based on risk—i.e., the degree of hazard (severity) and the likelihood of an accident occurring (probability).  All eye and face protection must meet the Basic Impact Testing Requirements of the latest version of the American National Standard for Occupational and Educational Personal Eye and Face Protection Devices ANSI Z87.1 (these eye protection devices are marked “Z87”).  Where there is a possibility of a hazard from flying particles, the eye protection must meet the High Impact Testing Requirements of Z87.1 (this eye protection is marked “Z87+”).  An EH&S Industrial Hygienist may be consulted to provide guidance in selecting the proper protection.

Safety Glasses

• Safety glasses with side shields are required to be worn by individuals while handling or using chemicals.  They must meet the basic impact-resistance provisions of ANSI Z87.1.
• They are the minimum protection required when handling chemicals.   Safety glasses must be supplemented with goggles and/or face shields when there is a greater risk of exposure to chemical splashes or flying particles (e.g., when pouring or mixing chemicals or cryogens).
• Contact lenses may be worn in work areas.  However, contact lenses do not provide eye protection.  Safety glasses or goggles must be worn by people who use contact lenses when chemicals are being handled.

Cover Goggles

Cover goggles are required for operations where there is a greater risk of exposure to chemicals and to flying particles.   Furthermore, they are required for activities producing airborne eye irritants including gases, vapors, fumes, dusts, and mists.  Safety glasses provide no protection against eye irritants.

Cover goggles are available in several varieties including:

• Direct-vented: These allow air flow for comfort and to reduce fogging.  Generally, direct-vented goggles are inappropriate for liquid chemical use because the vent ports may allow splashed liquids to pass through. Moreover, they provide no protection against airborne eye irritants (gases, vapors, fumes, dusts, and mists).
• Indirect-vented: These allow air flow for comfort and to reduce fogging.  These are appropriate for liquid chemical use and will protect the eyes from splashes.  However they will not guard against irritating gases, vapors, fumes, dusts, and mists.
• Non-vented: These have no vents and are required for operations that produce airborne irritating gases, vapors, fumes, dusts, and mists.  They also protect against chemical splashes to the eyes.

Face Shields

• Face shields protect the entire face and are required for operations that present a high likelihood of exposure to flying particles or splashes from liquid chemicals or cryogenic fluids.
• Face shields must be worn in conjunction with safety glasses or chemical goggles, because face shields can be lifted up during use, exposing the eyes to hazards.

Respirators

• Respirators should not be needed in most laboratory and shop settings.  However, if engineering, work practice, and administrative controls are not adequate to minimize an airborne chemical hazard, respiratory protection is required.
• Use of respirators requires a hazard evaluation conducted by an Industrial Hygienist.  All respirator users must be medically qualified, trained, and fit-tested to wear respiratory protection equipment. 
• An Industrial Hygienist must approve procurement of respirators.
• Any questions regarding the need for or use of respirators should be directed to an EH&S Industrial Hygienist.   LBNL respirator policy may be found in PUB-3000, Chapter 19, “Respiratory Protection Program.”

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