OEH&S Chemical Safety Manual Chapter 5

ADMINISTRATIVE AND ENGINEERING CONTROLS AND PERSONAL PROTECTIVE EQUIPMENT

Personnel exposures can be eliminated, or substantially minimized by use of proper protective controls. These controls can be divided into three categories: administrative controls, engineering controls, and personal protective equipment - each is discussed below.

A. ADMINISTRATIVE CONTROLS

Administrative controls are those written and verbal policies, plans, and procedures which provide general direction for safe work practices. This Chemical Safety Manual is one element of the administrative controls at the University of California, San Francisco (UCSF). Other documents which the Office of Environmental Health and Safety (OEH&S) provides include the periodic newsletters, flyers on specific topics of safety concern, and training manuals.

Many administrative controls are specific to the research being conducted, and are the responsibility of the Principal Investigator or the Laboratory Manager. This should include Standard Operating Procedures (SOPs) for all laboratory procedures done repeatedly. SOPs should include appropriate safety instructions, such as personal protective equipment to be used, special cautions for any highly hazardous chemicals, instructions to perform procedures in a fume hood.

Signs, labels, and other postings also are classified as administrative controls. Their presence in the laboratory provides workers and visitors with critical information concerning hazards present in that laboratory. Examples of signs and labels commonly used in laboratories can be found in Appendix E.

Training is yet another example of an administrative control. Principal Investigators or Laboratory Managers are responsible for training personnel in proper operations of all equipment, performance of laboratory procedures, and recognizing and dealing with other hazards in the workplace. Training is discussed further in Chapter 6. Failure to follow procedures is the most common cause of accidents.

B. ENGINEERING CONTROLS

Engineering controls are measures which are incorporated into the design of the facility to eliminate or reduce personnel exposure to chemicals. These measures are the preferred methods and must be used as primary means of achieving exposure control. Engineering controls are intended to protect all personnel working in the area.

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1. VENTILATION

Adequate ventilation in a laboratory, or other chemical use or storage area, is critical in the exposure control program. The following is a general description of how this can be achieved. UCSF OEH&S reviews construction plans to evaluate the specific needs of each facility.

2. GENERAL LABORATORY VENTILATION

This system should provide a source of air for breathing and for supply to local ventilation devices; it should not be relied upon for protection from toxic substances released in the laboratory. The general laboratory ventilation system should ensure that laboratory air is continually replaced, preventing increase of air concentrations of toxic substances during the working day; it should direct air flow into the laboratory from non-laboratory areas and out the exterior of the building.

3. FUME HOODS

The primary form of protection from overexposure by inhalation in laboratories is the fume hood. Most laboratories are equipped with at least one negative pressure fume hood that pulls vapors of hazardous chemicals away from the user.

The Chemical Hygiene Plan (CHP) states that whenever exposure by inhalation is likely to exceed the threshold limits described in the MSDS for that particular chemical, a fume hood should be used. Therefore, before using a compound, check the MSDS for that compound to determine whether it should be used exclusively in a fume hood.

a. Before Using a Fume Hood

Check to see that it is working properly. This can be accomplished by closing the sash to within one inch of being completely closed and taking a small strip of tissue and placing it near the one inch opening. If the hood is working, the strip of tissue should be drawn into the hood, demonstrating negative pressure. If the strip does not show negative pressure, then inform the lab supervisor or Building Manager and OEH&S.

b. Fume Hood Filtering Requirements

Certain chemicals require that the fume hood in which they are used have a filtered exhaust system. To determine if other chemicals require special filtration, the Department Safety Advisor at OEH&S can be contacted to ascertain requirements.

Note that fume hoods used for radioisotope work (specifically iodination and / or xenon studies) at the Laurel Heights and Mount Zion locations must be filtered. The filter system must be approved by the Radiation Safety Officer prior to installation and use.

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c. User Responsibilities

Ensure proper use. The quality of protection afforded by the fume hood is invariably affected by the manner in which the fume hood is used. A training video is available through Environmental Health and Safety (OEH&S). Viewing may be arranged by contacting your DSA.

1. Maintain sash and/or sash-panels in proper position.
2. Never remove sliding sashes which are permanently installed on fume hoods.
3. Make sure that the vertical sash is lowered to the marks that OEH&S has indicated on the hood. This mark corresponds to a face velocity meeting the Cal-OSHA requirements. This also provides splash protection from the operation being performed.
4. The face velocity of the hood is dependent on the sash being in the proper position. If the face area of the hood is increased by sliding the sash too high, the face velocity will be lowered which reduces the capacity of the fume hood to capture and control airborne chemicals used inside of it. Decreasing the face area by pulling the sash down too low generally increases the face velocity. Increased velocities may create eddy currents around the body of the hood user and around articles inside the fume hood which may draw materials out of the hood and into the room, thereby compromising the protection the hood is designed to provide.
5. Confirm that the flow is sufficient in the hood by checking the testing sticker and magnehelic gauge. The testing sticker should show that the hood has been tested within the last year and that the indicated flow rate average air velocity is above 100 fpm (150 fpm for carcinogen use). The magnehelic gauge should show a pressure consistent with previously observed acceptable readings (e.g. those readings that have a check mark in the column with the heading "OK").
6. Do not put your head in the fume hood, particularly when there are contaminants in the hood.
7. Perform work in a shallow tray if possible. If the hood does not have a recessed work area, minor spills will be contained in the tray or will serve to minimize spillage out onto the lab floor.
8. Locate the procedure, experiment or apparatus as deeply as possible within the hood. This will act to maximize the efficiency of the hood.
9. Keep the fume hood free of extraneous materials. Only those materials necessary to the procedure or experiment should be in the hood while work is being conducted.
10. Do not block the slots between the air flow distribution baffles by excess storage of containers in the hood. Blocking the baffles disrupts the air-flow distribution and is an additional cause of poor fume hood performance.
11. NEVER EVAPORATE PERCHLORIC ACID IN AN ORDINARY HOOD. Perchloric acid evaporation requires the use of a specifically designed hood with water-washdown capability (see Appendix F2 Safe Handling Guide for Perchloric Acid and Perchlorates). Failure to do this will result in the deposition of perchlorate crystals in the duct work, these crystals may detonate.
12. Never perform repairs or make mechanical connections to an existing fume hood, fume hood ducting, or other local exhaust ventilation systems. The ventilation system may not have sufficient flow to handle the additional effluent and may disrupt other fume hoods and their users.
13. Never remove distribution baffles (panels) installed in the exhaust systems and at the rear and top of the fume hood. The purpose of these baffles is to properly distribute air flow over the hood opening and work area.
14. Never use a room or portable fan in a laboratory with a fume hood or local exhaust system. The air velocity developed by a room fan will disrupt the face velocity and overwhelm the ability of the fume hood to capture and control air contaminants generated inside.
15. If the door to the laboratory is difficult to open when the fume hood or local exhaust ventilation system is operating a "make-up" air problem may exist. This develops when an inadequate supply of air is delivered to the room to compensate for the air exhausted by the operating fume hood. Notify the Building Manager should this happen.
16. Do not paint or cover fume hood inspection stickers or sash opening indicators.
17. Do not locate a work station opposite a fume hood. Materials splattered or forced out of a hood during an accident could injure a person seated across an aisle from a hood.
18. Do not locate a work station where the only egress from the work station requires passage in front of the hood. A fire or chemical accident, both of which often start in a fume hood, can block an exit rendering it impassable. For this reason all labs are required to maintain two unobstructed means of egress.
19. Do not locate flammable/combustible storage cabinets directly under a fume hood. Storage of flammable and combustible liquids under a fume hood creates a potential fire hazard due to the uses of open flames and electrical devices in the fume hood.
20. Use of portable hoods which can be inserted inside fume hoods for iodination procedures must be specifically approved by the Radiation Safety Officer.

Contact OEH&S at 476-1300 with any questions about user responsibilities or report any problems with the hood to your Building Manager.

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4. OTHER LOCAL VENTILATION DEVICES

Ventilated storage cabinets, canopy hoods, snorkels, and other ventilation devices may be provided as needed. Each canopy hood and snorkel should have a separate exhaust duct.

5. MODIFICATIONS

Any alteration of the ventilation system should be made only if thorough testing indicates that worker protection from airborne toxic substances will continue to be adequate. Contact OEH&S for approval prior to making any modifications.

C. GENERAL FACILITY DESIGN

The chemical storage and usage areas should also incorporate certain design features to provide adequate safeguards. These include:

• Appropriate and adequate storage space for both flammable and corrosive chemicals being used.
• Adequate work space, with sufficient aisle space.
• Benchtops which are impervious to chemicals being used.
• Properly designed storage shelves with lip to prevent toppling of chemicals in the event of an earthquake.
• Continuous vinyl floor coverings (tiles are unacceptable) with 4 inch covings to the walls.
• Sink with foot or elbow operated faucets.

  1. EMERGENCY DELUGE SHOWERS AND EYEWASH FOUNTAINS

  a. Deluge Showers

  i. Location:

  • Deluge showers are required "...at accessible locations that require no more than 10 seconds...” (CAL-OSHA requirement) for an injured person to reach in every laboratory using chemicals which are corrosive or severely irritating to the skin, or which are toxic to the skin, or toxic to other tissues by absorption through the skin.
  • A deluge shower shall be installed within all acid glass washing areas.
  • The path to the deluge shower must be unobstructed. A person with a chemical in his/her eyes cannot be expected to see well enough to open doors or avoid equipment.
  • No obstructions, protrusions, or sharp objects shall be located within 32 inches from the center of the spray pattern of the emergency shower facility.
  • No electrical outlets are permitted within 2.5 feet of the center of the spray pattern of the emergency shower facility.
  • Deluge shower locations are to be determined after consultation with OEH&S.

  ii. User Responsibilities:

  • All departments/institutes should ensure that their laboratories comply with the 10 second access requirement to the deluge shower.
  • All supervisors/Principal Investigators are expected to inform their staff as to the location(s) of the accessible deluge shower(s) and the importance of removing contaminated clothing and flushing the contaminated area for at least 15 minutes should an accident occur. (See Appendix F1, Safe Handling Guide for Corrosive Chemicals, for additional information.)
  • All supervisors/Principal Investigators should ensure that the testing tag on the deluge shower is current and that the activating mechanism is in proper working order. Contact OEH&S, 476-1300, if a deluge shower needs to be tested.
  • All supervisors/Principal Investigators should ensure that deluge showers are not blocked or obstructed.

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  iii. OEH&S Responsibilities:

  • Testing of deluge showers is the responsibility of OEH&S.
  • Showers must be activated on a monthly basis.
  • Testing date is recorded on the tag and on the inspection/survey sheet.
  • User and Mechanical/Performance Deficiencies:
  • User Deficiency. If the deficiency resulted from improper use (see "user responsibilities") a copy of an improper use notice will be sent to the user and department chairman informing them of the type and nature of the deficiency.
  • Mechanical/Performance Deficiency. OEH&S will notify Facilities Management of the deficiency in writing within 24 hours of identification of the deficiency.
  • Deficiency correction:
  • Upon written notice from Facilities Management, OEH&S will retest the deluge shower within 24 hours of receipt of notice.
  • The shower will be recertified, if upon retesting the shower deficiencies have been corrected and no further deficiencies exist. If the corrections have not been properly made, Facilities Management will be re-notified.

  iv. Facilities Management Responsibilities:

  • Facilities Managers are responsible for repairs to the deluge shower and shower system.
  • Facilities Management Staff making the correction are responsible for recording the repairs made on the survey form (sent to Facilities Managers by OEH&S) and signing and dating the form when completed. The form must be returned to: Deluge Shower Safety Program OEH&S, Box 0942 50 Medical Center Way
  • Facilities Managers are responsible for notifying OEH&S of all construction involving new or relocated showers.
  • If general maintenance or repair requires the shut down of a shower or shower system, Facilities Management is responsible for notifying the Principal Investigator or the Laboratory Supervisor of the time and duration of the shut down.This shall be accomplished by sending a notice directly to the Principal Investigator or Laboratory Supervisor and posting a written notice on the shower to allow laboratory personnel to prepare in advance for the shutdown.

  b. Eyewash Fountain

  i. Location:

  • An eyewash fountain is required to be in “…accessible locations that require no more than 10 seconds…” (Cal-OSHA requirement) for an injured person to reach in every laboratory using chemicals which are corrosive or severely irritating to the skin, or which are toxic to the skin, or toxic to other tissues by absorption through the skin.
  • The path to the eyewash must be unobstructed. A person with a chemical in his/her eye cannot be expected to see well enough to open doors or avoid equipment.
  • The device must be designed so that users can activate the flow of water from the eyewash and have both hands free to keep the eye lids open during flushing.
  • No electrical outlets or electrical apparatus should be in the vicinity of the device.
  • No obstruction, protrusions, or sharp objects shall be located within 32 inches from the center of the eyewash.
  • Eyewash fountain locations are to be determined after consultation with OEH&S.

  ii. User Responsiblilities:

  • All departments should ensure that their laboratories comply with the 10-second access to the eyewash fountain requirement.
  • Principal Investigators/supervisors are ultimately responsible for the proper operation of all safety equipment, including eyewash fountains.
  • All Principal Investigators and supervisors are expected to inform their staff as to the location(s) of eyewash fountains and of the importance of flushing eyes for at least 15 minutes should an accident occur.
  • All Principal Investigators/supervisors should verify that the testing tag for the eyewash fountain is current, and that the activating handle for the eyewash fountain has been tested.
  • It is always prudent for the Principal Investigator/supervisor/user to test the eyewash fountain before beginning any work with an eye- or skin-damaging material.

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  iii. OEH&S Responsibilities:

  • Testing of eyewash fountains is a service provided by OEH&S. Eyewashes are flushed on a monthly basis, and calibrated for proper flow on an annual basis.
  • OEH&S is responsible for filling out the inspection date on the inspection record posted at the eyewash, and for recording the inspection in OEH&S’s eyewash testing records.

  iv. Facilities Management Responsibilities:

  • Facilities Managers are responsible for repairs to eyewash fountains and systems.

  2. DRENCH HOSES

  Drench Hoses do not meet regulation requirements for laboratory safety devices. Approved eye washes and deluge showers are required as described previously. OEH&S does not test drench hoses. Should a person choose to use a drench hose in an emergency, he / she must do so at personal risk. If drench hoses are used to supplement eyewashes and deluge showers, it is prudent that a responsible person flush the drench hoses periodically (at least monthly) and check proper function.

  3. PERSONAL PROTECTIVE EQUIPMENT (PPE)

  a. Protective Clothing

  i. Lab Coat

  The lab coat is designed to protect the clothing and skin from chemical spills or splashes. It should always be properly closed, slightly loose fitting and best if knee length. There are several different types of lab coats for different types of protection.

  • Cotton
    Cotton protects against flying objects, sharp or rough edges, and is a good fire retardant.
  • Wool
    Wool protects against splashes of molten materials, small quantities of acid, and small flames.
  • Synthetic fibers
    Synthetic fibers protect against sparks and infrared and ultraviolet radiation. However, synthetic fiber lab coats can adversely magnify the effects of some laboratory hazards. For instance, some solvents may dissolve particular classes of synthetic fibers, thereby diminishing the protective ability of the coat. In addition, on contact with flames, some synthetic fibers will melt. This molten material can cause painful skin burns and release irritating fumes.
    
    The construction of the material must also be considered (twill, felt, plain, etc.), as the materials are rated differently by various manufacturers. Lab coats should be made with snaps/fasteners for closure which afford the wearer quick removal in the event of an emergency. Lab coats should be worn only in the laboratory work area. These garments should not leave the work site.

  ii. Aprons

  An apron provides an alternative to the lab coat. It is usually made of plastic or rubber to protect the wearer against corrosive materials and irritating chemicals. An apron should be worn over garments that cover the arms and body.

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  4. HEARING PROTECTION

  The Office of Environmental Health and Safety will respond to inquiries regarding noise exposure in the work place. Upon request, the staff of OEH&S will conduct environmental noise and/or personal exposure dosimetry. Ear protection should be worn where the noise level is above 85 decibels (dBa), eight hours time - weighted average. Areas where excessive noise is present should be posted with signs indicating ear protection is required. Ear protectors should be readily available and composed of rubber or plastic.

  a. Types of Ear Protection Include:

  1. Ear plugs
     Ear Plugs provide basic protection to seal the ear against noise.
  2. Ear muffs
     Ear Muffs provide protection against noise, and may be more comfortable than ear plugs.
  3. Cotton inserts
     Cotton inserts are poor suppressers of noise and should be avoided.

  5. EYE PROTECTION

  The number one safety precaution is Safety Goggles. All students, laboratory assistants, instructors, stockroom personnel, and visitors in the chemical storage areas, and laboratory and lecture preparation areas are required to wear safety goggles. Appropriate eye protection is necessary when there is a chance of spraying or splattering a chemical or exposure to UV light or LASER. When working with a dry powder reagent, a dusty situation could allow particulate matter to enter your eyes.

  Wearing contact lenses in the lab is acceptable and does not create an additional hazard for the wearer. However, appropriate safety goggles must be worn. Some soft lenses do absorb organic vapors and corrosive vapors like hydrogen chloride or ammonia. If you are wearing contact lenses and notice any discomfort while working with volatile solvents, or corrosive liquids or gases then the lenses should be removed.

  6. FOOT PROTECTION

  Foot protection is designed to prevent injury from corrosive chemicals, heavy objects, electrical shock, as well as giving traction on wet floors. If a corrosive chemical or heavy object were to fall on the floor, the most vulnerable portion of the body would be the feet.

  When selecting footwear for the lab, choose sturdy leather shoes that cover the foot. These will provide the best protection.

  The following shoe types should not be worn in the laboratory:

  • Sandals
  • Clogs
  • High heels
  • Shoes that expose the foot IN ANY WAY

  Safety Toe Shoes (steel toed) are recommended for activities such as lifting heavy objects, using power tools, etc. They can protect against crushing injuries caused by impact from any object during work activities.

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  7. HAND PROTECTION

  It is a good idea to always wear protective gloves in the laboratory.

  Because certain glove types can dissolve in contact with solvents, it is important to match the type and material of the protective glove with the nature of the job. Before use, check to make sure the gloves (especially latex gloves) are in good condition and free from holes, punctures, and tears.

  a. Glove Types and Removal

  Gloves should be selected on the basis of the material being handled and the particular hazard involved.

  1. Plastic
     Plastic protects against light corrosives and irritants.
  2. Latex
     Latex provides light protection against irritants.
  3. Natural Rubber
     Natural Rubber protects against light corrosive material and electric shock.
  4. Neoprene
     For working with solvents, oils, or light corrosive material.
  5. Cotton
     Cotton absorbs perspiration, keeps objects clean, provides some fire retarding properties.
  6. Zetex
     When handling small burning objects, these are a good replacement for asbestos gloves.

  When working with extremely corrosive material, wear thick gloves or more than one pair of gloves. Take extra precaution in checking for holes, punctures, and tears.

  Care should be taken when removing gloves. Peel the glove off the hand, starting at the wrist and working toward the fingers. Keep the working surface of the glove from contacting skin during removal. Disposable gloves should be discarded in designated containers. Hand washing following glove removal is always prudent. Do not wear gloves outside lab areas.

  8. RESPIRATORY PROTECTION

  When engineering controls cannot successfully minimize or eliminate the potentially harmful fumes, a respiratory protection program should be established. Contact OEH&S for assistance.

  a. Respiratory Protection Program

  A respirator program must cover many issues, including:

  1. Medical evaluations.
  2. Education and training in the use of respiratory equipment.
  3. Proper storage and cleaning practices to ensure optimum protection.
  4. Equipment adjustment to assure the user of a proper fit and to maximize protection against fumes and contaminants. If you think your lab procedures require respiratory protection, contact OEH&S for assistance.

  b. Respirator Types

  There are many respirator types available to laboratory workers. These protective devices range from a disposable dust mask to a self contained breathing apparatus (SCBA). Further information on specific types may be obtained from OEH&S.

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