HAZ Hazardous Substance Removal Certification in California

Updated November 1, 2026 · Official name from CSLB's classification list

• 1,825licenses hold HAZ
• 97.7%Clear (CA addresses)
• 26.5%workers' comp exempt (all: 49.6%)
• 99.9%contractor's bond on file
• 22.8 yrsmedian time licensed
• 78.5%businesses, not sole owners

HAZ is a certification, not a license on its own. It gets added to an existing license when the qualifier passes CSLB's hazardous substance certification exam under BPC §7058.7. CSLB's current application lists the eligible classes as A, B, C-12, C-21, C-36, C-57 and C-61/D-40.

The certification covers removal or cleanup that requires digging and hauling away soil at a listed hazardous-waste site, plus installing or removing underground storage tanks. It excludes asbestos work and highway spill cleanup. Few homeowners need it, except for an old buried heating-oil or fuel tank. Tank removal is often bid by a general engineering or C-12 firm.

Typical work under HAZ

• Removing underground fuel or heating-oil tanks
• Installing underground storage tanks
• Excavating and hauling contaminated soil at listed sites
• Remedial cleanup work at state or federal listed sites
• Service station tank work under C-61/D-40

Work that needs a different license

• Asbestos removal: C-22 Asbestos Abatement or the ASB certification
• Demolishing the building above the tank: C-21 Building Moving/Demolition
• Repaving after the tank is out: C-12 Earthwork and Paving

Tips before hiring

• Look for "HAZ" on the license record before hiring for tank removal.
• A contractor without HAZ may bid on a tank job, but the work must be done by a certified contractor. Ask who that will be.
• Ask who will handle testing, permits and closure paperwork with the local agency.

Where HAZ contractors are

The cities with the most HAZ license holders in CSLB's current file:

1. San Francisco: 42
2. Bakersfield: 41
3. Los Angeles: 38
4. Sacramento: 35
5. San Diego: 31
6. Anaheim: 28
7. Fresno: 26
8. Irvine: 25
9. Oakland: 25
10. Riverside: 22

How to verify a HAZ license

1. Search the business or license number here and confirm HAZ is listed on the profile as a certification.
2. Check the same number on CSLB's Instant License Check.
3. Read our full guide to checking a contractor license.

Related license types

• A General Engineering Contractor
• C-12 Earthwork and Paving Contractors
• C-21 Building Moving/Demolition Contractor
• C-36 Plumbing Contractor
• C-57 Well Drilling Contractor

Source: CSLB public data · Updated November 1, 2026 Status can change at any time. Verify on CSLB's Instant License Check.

More license types: ← ASB Asbestos Certification · A General Engineering Contractor →