California Hazardous Materials Business Plan (HMBP) Requirements

Short answer: a California business that handles hazardous materials at or above 55 gallons (liquids), 500 pounds (solids) or 200 cubic feet (compressed gas) at any one time during the year must prepare a Hazardous Materials Business Plan (HMBP) and file it electronically in CERS with its local CUPA (Health and Safety Code §25507; statute text checked Oct 2026). Most small facilities then resubmit every three years; Tier II and aboveground-petroleum facilities resubmit every year, due March 1 unless the CUPA sets another date (§25508).

California meets the federal EPCRA chemical inventory requirement through the HMBP, so for most businesses this is the California version of Tier II — see Tier II and HMBP in California for how the two relate.

Who must file: the thresholds

Section 25507(a) requires a business plan if the business handles, at any one time during the reporting year:

• a hazardous material or mixture at or above 55 gallons of liquid, 500 pounds of solid, or 200 cubic feet of compressed gas at standard temperature and pressure;
• an extremely hazardous substance (40 CFR 355) at or above its threshold planning quantity, where that quantity is under 500 pounds;
• a solid or liquid that is hazardous solely as an irritant or sensitizer at or above 5,000 pounds or 550 gallons;
• 1,000 cubic feet or more of certain gases: simple asphyxiants, carbon dioxide, nonflammable refrigerant in a refrigeration system, gas in a closed fire suppression system, and oxygen, nitrogen or nitrous oxide kept by a physician, dentist, podiatrist, veterinarian, pharmacist or EMS provider;
• combustible metals, perchlorate material or radioactive material above the quantities the section sets; or
• any quantity that already requires it to submit federal Tier II inventory information.

The mixture's physical state as a whole decides which threshold applies, and a “business” includes nonprofits and public agencies, not only companies. A hazardous material includes anything that requires a safety data sheet under California Labor Code 6360 — which is why the inventory usually starts from your SDS binder.

Common exemptions

Section 25507(b) exempts, among others:

• refrigerant (other than ammonia or flammable gas) in closed comfort-cooling or computer-room cooling systems;
• lubricating oil, if no single type exceeds 55 gallons and all types together do not exceed 275 gallons;
• consumer products at a retail store for direct sale to the end user (with limits for NFPA/HMIS 3–4 rated products stored in large quantities);
• propane up to 500 gallons used only for cooking, heating work areas and heating water on site;
• fuel in the tanks of vehicles and motorized equipment.

Your CUPA can still require reporting in some of these cases, and CUPAs may adopt stricter local rules.

What goes in the plan

Section 25505 and CalEPA's HMBP guidance require four parts:

• Hazardous materials inventory — every reportable material handled at the facility during the year.
• Site map — north orientation, adjacent streets, access and exit points, evacuation staging areas, hazardous material handling and storage areas, emergency response equipment and, if present, loading areas, internal roads, storm and sewer drains and emergency shutoffs.
• Emergency response plans and procedures — immediate notification contacts, procedures to mitigate a release, and evacuation plans for the site. CalEPA publishes an optional Consolidated Emergency Response / Contingency Plan template.
• Employee training — training for all new employees and annual refresher training in safety procedures for a release, documented and kept for at least three years.

When to submit, and when to update

Submission cycle (§25508(a)). A facility that must report federal Tier II information, or that is subject to the Aboveground Petroleum Storage Act, submits its plan annually. Every other facility submits once every three years. The deadline is March 1 of the year the plan is due unless the CUPA sets a different date. If the CUPA finds the plan deficient, a corrected plan is due within 30 days of its notice.

Updates within 30 days (§25508.1) are required after:

• a 100 percent or more increase in the quantity of a previously disclosed material;
• handling a previously undisclosed hazardous material;
• a change of business address, ownership or name;
• a substantial change in operations that would affect emergency response or the plan.

Many older guides still say the plan is certified every year. That was true before section 25508 was amended (the current text has been in force since January 1, 2020); check the cycle that applies to your facility, and confirm the date with your CUPA.

Where the inventory comes from

The hardest part of an HMBP is usually the inventory: what you have, how much at peak, its physical state and its hazard classes. All of that is on the safety data sheets for the products on site, so a current SDS binder is the starting point — see how to build a chemical inventory from scratch. SDSentry keeps that chemical list and its sheets current; it does not file in CERS for you.

Frequently asked questions

Who needs a Hazardous Materials Business Plan in California?

Under Health and Safety Code section 25507, a business must establish an HMBP if at any one time during the year it handles a hazardous material at or above 55 gallons of liquid, 500 pounds of solid or 200 cubic feet of compressed gas, or an extremely hazardous substance at or above its federal threshold planning quantity, among other triggers. Higher thresholds apply to materials that are hazardous only as irritants or sensitizers and to certain simple asphyxiant and medical gases.

Where do you file an HMBP?

Electronically in CERS, the California Environmental Reporting System. It is administered by your local Certified Unified Program Agency (CUPA), which may have requirements stricter than the state's.

How often do you have to submit an HMBP?

Under section 25508, a facility that must report federal Tier II information, or that is subject to the Aboveground Petroleum Storage Act, submits annually. Other facilities submit once every three years. The due date is March 1 unless your CUPA sets a different date.

When do you have to update an HMBP?

Within 30 days of a 100 percent or more increase in a previously disclosed hazardous material, handling a previously undisclosed hazardous material, a change of business address, ownership or name, or a substantial change in operations that would affect emergency response.

What does an HMBP include?

A hazardous materials inventory, a site map, emergency response plans and procedures, and an employee training program. Training covers new employees and annual refresher training, and training records must be kept for at least three years.

Are retail consumer products exempt from HMBP reporting?

Consumer products handled at a retail establishment for direct sale to the end user are generally exempt, but not at a manufacturing site or a warehouse with no direct sales, and not for products rated 3 or 4 by NFPA or HMIS stored at or above 165 gallons of liquid, 600 cubic feet of gas or 1,500 pounds of solid.

This guide summarises the cited rules for general information and is not legal advice.

Related guides

• Tier II and HMBP Chemical Reporting in California
• EPCRA Tier II Reporting: Does Your Facility Need to File?
• How to Build a Chemical Inventory From Scratch
• OSHA Safety Data Sheet Requirements for Employers
• OSHA HazCom Compliance Checklist for Small Facilities