Chemical Hazards and Toxic Substances

Controlling Exposure

The following references aid in controlling workplace hazards associated with chemical hazards and toxic substances.

Overview of Controls

Controlling exposures to chemical hazards and toxic substances is the fundamental method of protecting workers. A hierarchy of controls is used as a means of determining how to implement feasible and effective controls.

OSHA’s longstanding policy is that engineering and work practice controls must be the primary means used to reduce employee exposure to toxic chemicals, as far as feasible, and that respiratory protection is required to be used when engineering or work practice controls are infeasible or while they are being implemented.

Where possible, elimination or substitution is the most desirable followed by engineering controls. Administrative or work practice controls may be appropriate in some cases where engineering controls cannot be implemented or when different procedures are needed after implementation of the new engineering controls. Personal protection equipment is the least desirable but may still be effective.

Type of Control	Examples
Elimination/Substitution	Substitute with safer alternatives. [See Transitioning to Safer Chemicals: A Toolkit for Employers and Workers]
Engineering Controls (implement physical change to the workplace, which eliminates/reduces the hazard on the job/task)	Change process to minimize contact with hazardous chemicals. Isolate or enclose the process. Use of wet methods to reduce generation of dusts or other particulates. General dilution ventilation. Use fume hoods.
Administrative and Work Practice Controls (establish efficient processes or procedures)	Rotate job assignments. Adjust work schedules so that workers are not overexposed to a hazardous chemical.
Personal Protective Equipment (use protection to reduce exposure to risk factors)	Use chemical protective clothing. Wear respiratory protection. [See the Respiratory Protection Safety and Health Topics page] Use gloves. Wear eye protection.

Additional Information

Permissible Exposure Limits - Annotated Tables. OSHA. OSHA has annotated the existing Z-Tables with other selected occupational exposure limits. OSHA has chosen to present a side-by-side table with the Cal/OSHA PELs, the NIOSH Recommended Exposure Limits (RELs) and the ACGIH® TLVs® which provides employers, workers, and other interested parties a list of alternate occupational exposure limits that may serve to better protect workers.
Hazard Communication. OSHA Safety and Health Topics Page. Provides example HazCom programs, many training resources, as well as links to the proposed Globally Harmonized System of Classification and Labeling of Chemicals (GHS).
Hazard Communication: Small Entity Compliance Guide for Employers That Use Hazardous Chemicals. OSHA Publication 3695, (2014).
Process Safety Management. OSHA Safety and Health Topics Page. Contains requirements for the management of hazards associated with processes using highly hazardous chemicals included in the Process Safety Management of Highly Hazardous Chemicals Standard (29 CFR 1910.119).
Sampling and Analysis. OSHA Safety and Health Topics Page. Describes chemical sampling and analysis used by occupational and safety professionals to assess workplace contaminants and associated worker exposures.
Chemicals: Managing Chemical Safety in the Workplace. National Institute for Occupational Safety and Health (NIOSH) Workplace Safety and Health Topic. Provides information on many hazardous chemicals and chemical concerns.
Recommendations for Chemical Protective Clothing: A Companion to the NIOSH Pocket Guide to Chemical Hazards. National Institute for Occupational Safety and Health (NIOSH). Identifies protective clothing materials appropriate for chemicals listed in this pocket guide.
A Guide for Evaluating the Performance of Chemical Protective Clothing. U.S. Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 90-109, (June 1990). Includes selection and evaluation guidelines for protective clothing.
Report To Congress On Workers' Home Contamination Study Conducted Under The Workers' Family Protection Act (29 U.S.C. 671a). U.S. Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH), (September 1995). Summarizes the hazards to which a worker's family may be exposed.