CHEMICAL SAFETY

Maria J. Doa

Information on chemical hazards and methods to reduce exposure are important elements to safely working with hazardous chemicals in laboratories as well as in other workplaces.  This document focuses on hazard communication and tools and requirements to minimize exposures to chemical hazards.

Hazard Communication

The OSHA Hazard Communication Standard (Ref. 1) requires evaluating the potential hazards of chemicals and communicating information concerning those hazards and appropriate protective measures to employees. The standard includes provisions for the following:

• Developing and maintaining a written hazard communication program for the workplace, including lists of hazardous chemicals present
• Labeling of containers of chemicals in the workplace
• Preparation and distribution of safety data sheets to workers
• Development and implementation of worker training programs regarding hazards of chemicals
• The use of appropriate protective measures when handling the chemicals

Safety Data Sheets

The Safety Data Sheets (SDS) for each hazardous chemical must include general information about the chemical for each of the following topics:

• Chemical identification
• Hazard(s) identification
• Composition and mixture information
• Safe handling and storage practices
• First aid measures
• Emergency control measures (e.g., firefighting)
• Physical and chemical properties
• Stability and reactivity information
• Toxicological information
• Exposure control and personal protection information

The SDS may also include information on proper disposal, environmental hazards, and regulatory information. For each topic, the SDS must also indicate if no relevant information was found.

Hierarchy of Controls

Occupational safety and health professionals use a framework called "hierarchy of controls" to select ways of dealing with workplace hazards, such as chemical hazards (Ref. 2). In this hierarchy, the types of measures that may be used to protect laboratory workers, prioritized from the most effective to the least effective, are:

1. Engineering controls
2. Administrative controls
3. Work practices
4. Personal protective equipment

Often a combination of control methods is necessary to minimize exposures to chemical hazards. A description of each type of control follows.

1. Engineering Controls

Engineering controls involve making changes to the work environment to reduce work-related hazards. These types of controls are preferred over all others because they make permanent changes that reduce exposure to hazards and do not rely on worker behavior. Engineering controls include protective equipment such as chemical fume hoods and glove bags. Specific measures should be taken to ensure proper and adequate performance of protective equipment.

2. Administrative Controls

Administrative controls are those that modify workers' work schedules and tasks in ways that minimize their exposure to workplace hazards. Examples of administrative controls are:

• Developing a Chemical Hygiene Plan, which provides guidelines for prudent practices and procedures for the use of chemicals, including the use of equipment, personal protective equipment, work practices capable of protecting workers, and provisions for medical consultation and examination when exposure to a hazardous chemical has or may have taken place
• Developing Standard Operating Procedures for chemical handling

3. Work Practices

Work practices are procedures for safe and proper work that are used to reduce the duration, frequency, or intensity of exposure to a hazard. An example of a work practice is chemical substitution where feasible (e.g., selecting a less hazardous chemical for a specific procedure).

4. Personal Protective Equipment

Personal protective equipment (PPE) is protective gear needed to keep workers safe while working with a chemical. Examples of PPE include respirators, face shields, goggles, protective clothing, and disposable gloves. While engineering and administrative controls and proper work practices are considered to be more effective in minimizing exposure to many chemical hazards, the use of PPE may also be very important.  It is critical that the appropriate PPE be used for the type of chemical being used and for the level of exposure to the chemical.  PPE should be:

• Selected based upon the hazard to the worker
• Properly fitted and in some cases periodically refitted (e.g., respirators)
• Conscientiously and properly worn
• Regularly maintained and replaced in accord with the manufacturer's specifications
• Properly removed and disposed of to avoid contamination of self, others, or the environment
• If reusable, properly removed, cleaned, disinfected, and stored

Laboratory Standard

Many research laboratories are subject to regulation for the safety of workers in the laboratory (Ref. 3). The OSHA Occupational Exposure to Hazardous Chemicals in Laboratories standard, commonly referred to as the Laboratory Standard, applies to laboratories in the United States that conduct research and development and related analytical work. It does not apply to most quality control laboratories. The purpose of the Laboratory Standard is to ensure that workers in non-production laboratories are informed about the hazards of chemicals in the workplace and are protected from chemical exposures.

   The Laboratory Standard consists of five major elements:

• Chemical hazard identification
• Chemical Hygiene Plan
• Information and training
• Exposure monitoring
• Medical consultation and examinations

The Laboratory Standard requires that the employer designate a Chemical Hygiene Officer and have a written Chemical Hygiene Plan that is actively verified for continuing effectiveness. The Chemical Hygiene Plan must include provisions for worker training, chemical exposure monitoring where appropriate, medical consultation when exposure occurs, criteria for the use of PPE and engineering controls, and special precautions for particularly hazardous substances. The Chemical Hygiene Officer should be required to be responsible for implementation of the Chemical Hygiene Plan.

The Chemical Hygiene Plan must be tailored to reflect the specific chemical hazards present in the laboratory where it is to be used. Laboratory personnel must receive training regarding the Laboratory Standard, the Chemical Hygiene Plan, and other laboratory safety practices, including exposure detection, physical and health hazards associated with chemicals, and protective measures.

References

1. OSHA Hazard Communication Standard, 29 CFR 1910.1200.
2. OSHA, OSHA Brief: Hazard Communication Standard: Safety Data Sheets.
3. OSHA, Laboratory Safety Guidance, OSHA 3404-11R, 2011.