A Control Measure is an action aimed to eliminate a hazard. If the hazard you’ve identified can’t be eliminated, follow the Hierarchy of Controls to select the next-best control to mitigate the risk of an accident, incident, injury, or near-miss in the laboratory.
The Hierarchy of Controls prioritizes intervention strategies based on the premise that the best way to control a hazard is to systematically remove it from the workplace, rather than relying on employees to reduce their exposure. The types of control measures used to protect employees (listed from most effective to least effective) are: engineering controls, administrative controls, and personal protective equipment. The following guidelines have been adopted from wording found on the “Control Measures” webpage of the American Chemical Society Committee on Chemical Safety.
Elimination and Substitution are considered the most effective control measures. They are easiest to achieve for brand new processes. They can be more difficult to implement for existing processes, because new and/or more expensive equipment and materials may be required.
- Completely get rid of chemicals, materials, processes, and equipment that are unnecessary to your specific experiment. Check if your equipment is well-worn; check dates, and refer to manufacturer’s recommendations.
- Switch out processes, equipment, material, or other components, where applicable. Think about the amount of chemicals or potentially hazardous materials you are using. Can you reduce the amount and still achieve the desired result? Do not use damaged glassware or equipment.
- Some valuable tools to help lab workers determine safer chemical substances are:
- Reduce or remove hazards by separation in time or space. May be particularly helpful in a shared lab space where different types of chemicals are being used.
- Place the material or process in a closed system such as a glove box.
- Move hazardous materials to where fewer workers are present.
- Guarding and Shielding. Install guards to provide protection from moving parts or electrical connections. Shielding provides protection from potential explosions.
- Use fume hoods, exhaust ducts, and biosafety cabinets to reduce the risk of overexposure.
Administrative Controls. While engineering controls seek to eliminate hazards, administrative controls aim to minimize a lab worker’s exposure. Administrative controls are the existing safety rules and protocols put in place for workers in the lab to follow. Following are examples of administrative controls:
- Follow all Standard Operating Procedures and the Laboratory Housekeeping Checklist.
- Provide proper Training and Information.
- Conduct a Jobs Hazard Analysis prior to the start of a procedure.
- Exposure Limits. Achieved by observing both the concentration and time exposed to a harmful chemical or physical agent.
Personal Protective Equipment (PPE). Even though the Hierarchy of Control Measures indicates that PPE is the least effective control measure, it should absolutely be used in case other control measures fail. The success of PPE depends in part on whether or not lab workers actually use it properly.
- Safety eyewear, protective clothing (e.g., lab coats and gloves), and hearing protection are the most recognizable and most used PPE in the lab.
- PPE is always essential, and especially critical in the following circumstances:
- When engineering controls are not feasible or they do not totally eliminate a hazard.
- As a temporary control while engineering controls are being developed.
- In emergency situations.