GENERAL PRINCIPLES FOR CONTROLLING CHEMICAL EXPOSURES
The hierarchy of hazard controls includes:
- Elimination (including substitution): remove the hazard from the workplace.
- Engineering controls include designs or modifications to equipment, ventilation systems, and processes that reduce the potential for exposure.
- Administrative controls alter the way the work is done, including timing of work, policies and other rules, and work practices such as standards and operating procedures.
- Personal protective equipment is worn by individuals to reduce exposure such as contact with chemicals or exposure to noise.
The use of engineering controls is the preferred method for reducing worker exposure to hazardous chemicals. Examples include but are not limited to:
- Isolation or enclosure of a process or operation.
- Use of wet methods to reduce generation of dusts or other particulates.
- General dilution ventilation.
- Local exhaust, including the use of ventilation hoods and glove boxes.
Evaluation of control measures:
- Air sampling for evaluating exposure to chemical substances shall be conducted periodically or as required by regulation.
- Air sampling shall be conducted if there is reason to believe that exposure levels for regulated substances exceed the action level, or in the absence of an action level, the permissible exposure level (PEL).
- The PEL is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent. For chemicals, the chemical regulation is usually expressed in parts per million (ppm), or sometimes in milligrams per cubic meter (mg/m3).
- The University follows the ACIGH or most restrictive established limit.
- Results of any air sampling studies shall be communicated with the affected laboratory, unit and/or department and records shall be maintained by RMS.
Work Practice and Administrative Controls
Using good laboratory work practices help to eliminate the risk of exposure to chemicals. Examples include but are not limited to:
- Limit access to lab when hazardous work is being conducted.
- Training of lab personnel.
- Administrative controls involve rotating job assignments and adjusting work schedules so that workers are not overexposed to a chemical.
- Administrative controls can be used in conjunction with engineering controls and PPE controls to minimize exposures
Personal Protective Equipment (PPE)
When engineering and administrative controls are not feasible to minimize exposure, personal protective equipment, including gloves, eye protection, respirators and other protective clothing shall be used. Hygiene Practices shall be used to reduce the likelihood of accident or chemical exposure. Hands shall be washed after removing gloves and before leaving the laboratory area as soon as reasonably possible. See the Personal Protective Equipment page for more information.