VI. Industrial Hygiene
Purpose : Industrial Hygiene is the science of recognition, evaluation, and control of the environmental health hazards arising in the work place. The procedure describes how the company will evaluate and control the chemical hazards in the laboratory.
Material Safety Data Sheets specify the health hazards associated with a hazardous material. A professional Industrial Hygienist is needed to interpret this information, especially Permissible Exposure Limits (PEL's) and Threshold Limit Values (TLV's) in relationship to how hazardous materials are used in the laboratory environment.
Scope : Certain hazardous chemicals require an industrial hygiene study to determine the level of the hazardous chemical and extent of control needed to protect the employee. These efforts will be coordinated by the Chemical Hygiene Department. Where a question exists concerning employee exposure to hazardous materials, engineering controls, or personnel protection equipment, the CHO should be contacted immediately.
Procedures:
A. Employee Exposure Determination
1. In many of the lab procedures, multiple hazardous chemicals are used. However, the quantities are small and the duration of use is short. For these reasons, monitoring of the potential employee exposure due to airborne chemicals will be conducted if there is sufficient reason to believe that an exposure is possible. The following criteria will be used to determine if monitoring will be conducted.
a. The toxicity and volatility of the hazardous chemical in use. If a highly toxic or highly volatile material is handled during a procedure, these operations will be placed on a priority evaluation list to determine if sampling is needed.
b. The manner in which the lab procedure is conducted, i.e. procedures which must be conducted outside a lab hood or unventilated area, if toxic chemicals must be heated, procedures must be conducted in open vessels not closed containers.
c. Quantity of, and frequency at which a hazardous chemical is used in the lab.
d. Report of an employee experiencing signs or symptoms of exposure, such as skin or eye irritation, shortness of breath, headache, etc.
2. As required by the OSHA Lab standard, monitoring will be conducted if the above conditions could result in an employee's overexposure during use of the following chemicals regulated by OSHA.
a. OSHA Regulated Substances are the following:
- -Asbestos
- -4-Nitrobiphenyl
- -alpha-Naphthylamine
- -Methyl-chloromethyl ether
- -3,3'-Dichlorobenzidine and its salts
- -bis-Chloromethyl ether
- -beta-Naphthylamine
- -Benzidine
- -4-Aminodiphenyl
- -Ethyleneimine
- -beta-Propiolactone
- -2-Acetylaminoflurene
- -4-Dimethylaminoazobenzene
- -N-Nitrosodimethylamine
- -Vinyl Chloride
- -Inorganic Arsenic
- -Inorganic Lead
- -Benzene
- -1,2-Dibromo-3-chloropropane
- -Acrylonitrile
- -EthylenÁe oxide
- -Formaldehyde
3. Monitoring of employee exposure may also be conducted for any other chemicals used in the lab if the conditions stated under paragraph 1 are experienced.
4. The CHO will coordinate employee monitoring. The CHO should be contacted if the above conditions are observed or if plans for a new procedure or use of a new chemical could be expected to create any of the conditions stated above.
5. Appendix III designates the chemicals that are routinely monitored in each lab.
B. Personal Protective Equipment
1. Respirator. Selection, use, maintenance and storage of all respiratory protective equipment will be in accordance with the respiratory protection program developed for the university as Safety and Health Procedure.
2. Safety glasses will be worn at all times when working in any lab where hazardous chemicals are used. Additional requirements for eye protection, such as chemical splash guard, goggles, full face respirator, etc., will be determined by the lab SOP for use of the chemical.
3. Protective clothing requirements, such as, lab coats, protective gloves, coveralls, etc., will be determined by the lab SOP for use of that chemical.
C. Preventive Maintenance Programs
1. Exhaust Ventilation. The local exhaust ventilation system will be maintained on a quarterly basis by the Physical Plant. The evaluation will include:
a. Hood performance.
i. Use smoke tubes to visualize the air flow patterns within the hood. Excessive turbulence, uneven exhaust air flow patterns, effects of make-up air will be evident from the smoke tube evaluation.
- Measure the air velocity with a calibrated velometer. Make a series of measurements to assure the even distribution of the exhausted air steam. Air velocities should not vary more than 20%-25% over the face of the hood.
- Always perform this evaluation with the hood sash in the full open position. If adequate velocities are not attainable at the full open position, remove the hood from service until it can be maintained.
b. Exhaust fan.
i. Maintain the exhaust fan, e.g. drive belts, lubrication, etc.
ii. Observe proper direction of the fan rotation.
iii. Determine the condition of the fan blades.
- Check the performance of multi-speed fans,
solenoids, etc., which can affect the performance of the hood under different operating conditions.
c. Additions to the LEV systems. Whenever an additional hood or other ventilated equipment is added to the system, the entire system should be re-evaluated. Following the evaluation, if changes are necessary, they should be made to the system before it is returned to service.
2. Eyewashes and Safety Showers.
a. Eyewash and Safety Showers will be checked on a monthly basis by a designated individual in the lab.