HAZWOPER 40 vs 24

Both of these training designations fall under 29 CFR 1910.120 (e). The Hazardous Waste Operations and Emergency Response (HAZWOPER) 24 is mainly for short work durations at HAZWOPER designated sites. The main difference between HAZWOPER 40 vs 24 is that one allows a person to work at a contaminated site for a prolonged period of time. The other one does not. Because of the shorter work period, it is unlikely that a person will work around a hazardous substance(s) at or above its Permissible Exposure Limit (PEL). The PELs can be found in the Z tables of the Occupational Safety and Health Administration (OSHA) standard 1910.1000.

The HAZWOPER 40 training is designed to prepare individuals to work at contaminated sites while being exposed to hazardous substances at or above PELs. The training will go into a great deal of detail in wearing a Level A suit along with wearing either an inline respirator or a Self Contained Breathing Apparatus (SCBA). Donning and doffing Level A suit equipment usually takes 2 people. In contrast, a person trained to the HAZWOPER 24 level will likely wear Level C equipment when conducting work at a site. This equipment is usually donned and doffed by the person wearing it with no help from anyone else. After the initial 40 or 24 hour training is completed, each individual must go through site specific training by a qualified supervisor. The requirement is 3 days for the 40 hour course and 1 day for the 24 hour course which is another difference between HAZWOPER 40 vs 24. Hands-on training of Personal Protective Equipment (PPE) and other equipment is required for both – 40 hour and 24 hour.

During the 40-hour program, trainees receive in-depth instruction on topics such as toxicology, chemical hazard recognition, air monitoring, site control and decontamination, respirator selection and fit testing, and spill containment procedures. 

By contrast, the 24 hour HAZWOPER course is intended for workers who have occasional or limited exposure to hazardous materials, or whose work takes place in areas where contamination levels are well characterized and below PELs. These individuals may include environmental consultants, site visitors, heavy-equipment mechanics, surveyors, or support personnel who spend only brief periods within controlled areas.

While HAZWOPER 40 vs 24 share the same regulatory foundation, the depth of instruction and scope of hands-on experience differ significantly. The 40 hour certification qualifies workers for higher-risk operations where direct contact with hazardous materials is likely, whereas the 24-hour certification qualifies them for occasional or limited-risk involvement.

Regardless of level, OSHA mandates that all HAZWOPER-trained employees complete an 8-hour refresher course annually to maintain certification and stay current with evolving standards, new technologies, and best practices.

In summary, the 40 hour HAZWOPER course equips full-time hazardous waste site workers with the knowledge and field experience to perform cleanup and emergency response safely, while the 24 hour HAZWOPER course prepares occasional site workers to recognize hazards and protect themselves in lower-risk environments. Selecting the correct training level depends on the employee’s job duties, potential exposure, and the nature of the worksite—but both play an essential role in keeping workers safe, compliant, and prepared for hazardous operations.