40 Hour vs 24 Hour HAZWOPER: Which Do You Need?
Match your job role and exposure level to the right HAZWOPER course, with plain-English OSHA guidance and quick enrollment links..
If you’re deciding between the 40 Hour vs 24 Hour HAZWOPER course, use this guide to match OSHA expectations to your job duties and exposure level so you choose correctly the first time.
Understanding HAZWOPER requirements
OSHA’s HAZWOPER standard 29 CFR 1910.120 sets training based on the level of potential exposure during hazardous waste operations and emergency response. New workers typically complete an initial 24 or 40 hour course, followed by an annual 8 hour refresher. Supervisors also complete an additional supervisor course.
40 Hour vs 24 Hour: Key differences
The core difference is expected exposure. Higher and more frequent exposure (often with respirators or full PPE) aligns with the 40 Hour course. Limited or occasional exposure that does not normally require respirators aligns with the 24 Hour course. Always confirm with your employer or site safety plan.
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Who needs 40 Hour HAZWOPER
- Assigned to uncontrolled hazardous waste sites with higher exposure potential.
- Direct and frequent contact with hazardous substances.
- Respirators or higher-level PPE may be required by the safety plan.
- Cleanup, remediation, or similar higher-risk activities.
Training pattern: 40 hours initial + three days supervised field experience + annual 8 hour refresher.
Who needs 24 Hour HAZWOPER
- Support personnel entering controlled areas briefly.
- Drivers, surveyors, equipment operators, or similar lower-exposure roles.
- Tasks that do not normally require respirators or high-level PPE.
Training pattern: 24 hours initial + one day supervised field experience + annual 8 hour refresher.
Quick comparison
| Requirement | 40 Hour HAZWOPER | 24 Hour HAZWOPER |
|---|---|---|
| Exposure level | Higher and frequent | Lower and occasional |
| PPE & respirators | May be required | Typically not required |
| Supervised field experience | Three days | One day |
| Annual refresher | 8 Hour Refresher | 8 Hour Refresher |
| Supervisor training | 8 Hour Supervisor (plus annual refresher) | 8 Hour Supervisor (plus annual refresher) |
Always follow your site safety plan and your employer’s training policy.
FAQs
How do I decide between 40 Hour and 24 Hour HAZWOPER?
Match the training to your exposure. Higher exposure and PPE needs point to 40 Hour. Limited or occasional exposure points to 24 Hour. Confirm with your employer or the site safety plan.
Do I need supervised field experience after the class?
Yes. 40 Hour typically includes three days of supervised field experience. 24 Hour typically includes one day. Your employer manages this requirement.
How often is refresher training required?
Annually. Most workers complete the 8 Hour HAZWOPER Refresher each year.
Does the 8 Hour HAZWOPER Supervisor course replace the annual refresher?
No. The Supervisor course is an additional requirement for supervisors. You still complete the annual refresher, such as the Supervisor Refresher when required.
Where can I read the OSHA standard?
See OSHA 29 CFR 1910.120.
Last updated: October 2025
