Secondary Containment
Secondary containment is required when hazardous materials are stored in containers that could potentially leak or spill. It is necessary for materials that pose a risk to human health, safety, or the environment, and it is often mandated by regulations such as the EPA's SPCC rule. The requirements for secondary containment can vary based on the specific hazardous material and the regulations in place. For example, OSHA requires secondary containment for flammable liquids, while the EPA's SPCC rule applies to oil storage tanks. It is essential to review the specific regulations applicable to your location and the materials you are storing to ensure compliance with secondary containment requirements.
OSHA does not have one single “secondary containment” rule that covers every hazardous material in every workplace. Instead, requirements often depend on the specific material being used. For example, the storage of flammable and combustible liquids often requires spill control measures to protect employees from fire and explosion risks.
Secondary containment is necessary when a material poses a clear risk to workers if it were to leak. OSHA’s rules for flammable liquids specifically require safety measures like diking or drainage for certain storage setups to manage these risks. The goal of these rules is primarily to protect personnel from immediate dangers like fires or chemical reactions.
Simply having a Safety Data Sheet (SDS) for a chemical does not automatically mean OSHA requires a secondary containment system. Requirements are based on the actual severity of the hazard and whether the containment is a feasible way to fix a recognized danger. While OSHA focuses on worker safety, other agencies like the Environmental Protection Agency (EPA) may have their own separate containment rules focused on protecting the environment.
There is no universal OSHA formula for how much a containment system must hold. However, many facilities follow standards established by the EPA for hazardous waste storage. Under these federal rules, a containment system for containers must be large enough to hold whichever of these is greater:5
10% of the total volume of all the containers in the area.
100% of the volume of the single largest container.
The materials used to build the containment system are also important. For hazardous waste tanks, the structure must be made of or lined with materials that are chemically compatible with the substance being stored. This ensures the spill barrier won’t break down if it comes into contact with the chemical. Some rules also require the base of the containment area to be impermeable and free of cracks to prevent leaks from escaping.
The way a workplace handles spill containment often depends on how the materials are stored. For large, fixed storage tanks, employers typically use permanent structures like dikes or curbs. These barriers are often made of concrete or earth and are designed to hold spills and guide them toward a safe drainage area. Double-walled tanks are another engineering option that includes the backup containment as part of the tank’s own design.
For portable items like 55-gallon drums, businesses often use modular equipment like spill pallets or containment pads. While OSHA does not have a single rule mandating these specific tools for all chemicals, they are a common way to meet the safety requirements set by various regulatory programs. Keeping these systems in good repair is a standard part of workplace safety, as cracks or damage can prevent the system from working correctly during an emergency.