• Engineering controls are physical changes at the worksite to isolate or reduce hazards.
• Administrative controls are policies, such as scheduling, that reduce employee exposure to hazards.
• Work practice controls are best practices for performing job duties so as to minimize risk.

Control measures are essential to eliminating or reducing the hazards that are present at a hazardous waste site. The requirements for control measures are described in paragraph (g) of the Hazardous Waste Operations and Emergency Response (HAZWOPER) Standard.

Engineering controls

Engineering controls are physical changes at the site to isolate people from the hazard or otherwise eliminate or reduce the hazard on the job or during the task. Examples include:

• Changing a process to minimize contact with hazardous chemicals,
• Isolating or enclosing the process,
• Using wet methods to reduce generation of dusts or other particulates,
• Ventilating to dilute the air,
• Using fume hoods,
• Using remotely operated equipment, and
• Using pressurized cabs or control booths on equipment to isolate the employee.

Administrative controls

Administrative controls reduce the duration, frequency, and severity of exposure to hazards. These can include:

• Instituting job rotation,
• Shortening shift lengths,
• Limiting overtime,
• Requiring frequent breaks,
• Decreasing production rates,
• Increasing the number of employees assigned to a task, and
• Removing all non-essential employees from potential exposure during the opening of drums.

However, employee rotation should be a last resort in regard to radiation exposure or dose limits. The employer should only use this control if there is no other feasible way of complying with the airborne or dermal dose limits for ionizing radiation.

Safe work practices

Some common safe work practices at a hazardous waste cleanup site include:

• Not smoking, eating, drinking, chewing gum or tobacco, or applying cosmetics in contaminated areas;
• Not using matches or lighters in contaminated areas;
• Wetting down dusty operations;
• Exiting contaminated areas if conditions change or become unsafe;
• Allowing only essential personnel to enter an area during certain activities like drum opening;
• Staying upwind of hazards if possible;
• Sticking closely to the buddy system;
• Checking in and out of work zones through access control points; and
• Using only intrinsically safe equipment in potentially explosive atmospheres.

Some other general safe work practices include keeping work areas clean, putting away tools or equipment, using safe lifting techniques, and wearing personal protective equipment (PPE) properly.

What about PPE?

The process of eliminating or substituting hazards and putting engineering, administrative, and work practice controls in place will help to mitigate many hazards; however, when hazards remain, there’s one more control method to turn to — PPE.

According to paragraph (g)(1) and (2) of 29 CFR 1910.120 and 1926.65,to the extent feasible, employers must institute engineering controls and work practices to help reduce and maintain employee exposure at or below permissible exposure limits. When this is not feasible, engineering and work practice controls may be supplemented with PPE to keep employee exposures at or below permissible exposure limits or dose limits.

Further requirements

In addition, the provisions of 29 CFR 1910 Subpart G or 29 CFR 1926 Subpart D must be followed. These subparts regulate occupational health and environmental controls for general industry and construction, respectively.