This post explains what makes a hazardous material in California, when a business must file a Hazardous Materials Business Plan (HMBP), and what’s inside that plan. You’ll also learn the most common types of hazardous materials and how DOT classes help responders understand risk quickly.


Imagine this problem

Imagine a busy workplace: a repair shop with gas for tools, a janitor closet with strong chemical cleaners, and a warehouse with storage drums. One day, a container tips, leaks, or gets damaged. Now think about this question: How would firefighters know what they’re facing?

California’s rules are designed so businesses and the local program agency can plan ahead—based on material properties, quantity, and the likely hazard if something is released.


What counts as a hazardous material in California

California treats “hazardous material” broadly. In general, a substance can be regulated if it has characteristics that can create danger to people or the environment if released.

The basic characteristics used to decide if something is a regulated hazardous material include:

  • toxicity (can harm health)
  • flammability (can catch fire)
  • corrosivity (can eat away materials and skin)
  • reactivity (can cause dangerous reactions)
  • radioactive materials (included for regulated purposes)

California law also recognizes that a material may be regulated when its physical characteristics or quantity could threaten the environment.

The idea behind the phrase “because of its…”

A material can be hazardous because of its:
- physical properties
- chemical characteristics
- quantity
- (and in some cases) infectious characteristics


Common examples of hazardous materials businesses may handle

Many everyday business supplies can be hazardous. Common examples include:

Where you might see it Example hazardous material Why it’s a hazard
Cleaning areas Concentrated cleaning products, acids (like battery acid electrolyte) Corrosive
Garages and shops Gasoline, alcohols, lubricating oils Flammable or toxic risks
Cooling equipment Refrigeration gases for coolers and freezers Often regulated gas risks
Paint and maintenance Aerosol spray cans, paints, parts washer fluids Can be flammable or harmful
Medical and waste streams (where applicable) Infectious or toxic medical waste materials Infectious risk
Gas storage Compressed gases such as helium, nitrogen, oxygen, carbon dioxide Many compressed gas materials can be reportable depending on amount

What physical and chemical traits make a material hazardous

The hazards usually come from two kinds of clues: what the material is like, and how it might behave.

Physical properties that can make it hazardous

Physical properties can increase risk during a spill, leak, or handling event—especially when they relate to how easily a material spreads or causes harm.

Chemical characteristics that contribute to hazardous behavior

Chemical characteristics often include things like:
- tendency to burn (flammable behavior)
- ability to damage tissue or containers (corrosive behavior)
- tendency to react violently (reactive behavior)
- poisonous effects (toxic behavior)

Infectious characteristics that make it hazardous

Some materials are hazardous because they can carry germs. If a material contains or can spread bacteria or viruses, it becomes hazardous in a special way: infectious.


Does quantity change whether something is hazardous

Yes. The same chemical can be a minor concern at small amounts and a major danger at larger quantity levels.

California law explicitly considers quantity, concentration, and physical or chemical characteristics when deciding if a material poses a significant hazard.


What types of hazardous materials exist

Hazardous materials are often grouped by how they behave and what kind of harm they cause. A clear way to understand this is through common categories:

Category What it means in plain words Example pattern
Corrosive Eats through containers or burns skin Strong cleaners, battery acid
Ignitable Catches fire easily Flammable liquids, paint removers
Reactive Can explode or release dangerous fumes Materials that react with heat or water
Radioactive Can give dangerous radiation Radioactive materials
Toxic Poisonous effects to health Poisonous chemicals
Infectious Carries germs that can cause disease Medical waste like contaminated items

DOT classification for hazardous materials

For transport, the U.S. DOT classifies hazardous materials into hazard classes based on their properties. There are nine DOT hazard classes, including explosives, gas, and corrosives.

Here is the list of Class 1 through Class 8 shown clearly in the DOT scheme used for hazardous transport:

DOT class What it covers Divisions listed in common DOT summaries
Class 1 Explosives 1.1, 1.2, 1.3, 1.4, 1.5, 1.6
Class 2 Gas 2.1, 2.2, 2.3
Class 3 Flammable liquids (No divisions listed here in the summary)
Class 4 Other flammable substances 4.1, 4.2, 4.3
Class 5 Oxidizing substances and organic peroxides 5.1, 5.2
Class 6 Toxic and infectious substances 6.1, 6.2
Class 7 Radioactive material 7
Class 8 Corrosives 8

Explosives divisions

  • Division 1.1 Mass explosion hazard
  • Division 1.2 Projection hazard, not mass explosion
  • Division 1.3 Fire hazard with minor blast/projection, not mass explosion
  • Division 1.4 No significant hazard (explosion limited to package)
  • Division 1.5 Very insensitive substances with mass explosion hazard
  • Division 1.6 Extremely insensitive articles with no mass explosion hazard

Gas divisions

  • Division 2.1 Flammable gas
  • Division 2.2 Non-flammable, non-toxic gas (often inert, under pressure)
  • Division 2.3 Toxic gas

Other named divisions in the summary

  • Division 4.1 Flammable solid
  • Division 4.2 Substances liable to spontaneous combustion
  • Division 4.3 Substances that emit flammable gases in contact with water
  • Division 5.1 Oxidizers
  • Division 5.2 Organic peroxides
  • Division 6.1 Toxic substances
  • Division 6.2 Infectious substances

Hazardous Materials Business Plan in California

An HMBP is a planning document. It helps everyone prepare before something goes wrong.

When an HMBP is required

A facility must prepare an HMBP if, at any one time during the year, it uses, handles, or stores hazardous materials (including hazardous waste), in reportable quantities greater than or equal to:

Material type Reportable quantity threshold
500 pounds of a solid substance 500 pounds
55 gallons of a liquid 55 gallons
200 cubic feet of a compressed gas 200 cubic feet
Extremely hazardous substances threshold planning quantities

How the submission process changed since 2013

As of January 1, 2013, California requires HMBP information to be submitted through the California Environmental Reporting System (CERS) website. Paper submittals are no longer accepted.


What information an HMBP must include

An HMBP contains basic information about:
- the location
- the type of hazardous materials
- the quantity
- and the health risks

It also connects to statewide minimum standards and is enforced locally by the Environmental Programs Division as a certified CUPA.


Responsibilities of the Union City Environmental Programs Division

Union City’s Environmental Programs Division conducts routine inspections at businesses that must submit an HMBP.

Their inspection goals are to:
- ensure compliance with HMBP laws and regulations
- identify existing safety hazards that could contribute to an accidental spill or release
- suggest preventive measures to reduce spill or release risk


How often a business must review and recertify

After initial submission, the business must review and recertify its HMBP every year through CERS.


When an HMBP must be amended

If something changes, the plan must be updated.

A deficiency must be amended and submitted within 30 days if any section is found deficient.

Also, amendments must be submitted within 30 days for events such as:
- a 100% or greater increase in the quantity of a hazardous material listed on the inventory
- handling a reportable quantity of a previously undisclosed hazardous material
- deleting a previously disclosed hazardous material
- changes in storage, location, or use that could affect emergency response


The seven required sections of an HMBP

California’s HMBP includes seven sections:

Required section What it’s for
Business Activities form What the business does
Owner/Operator Identification form Who is responsible
Chemical Inventory Description form What hazardous materials are involved
Site Map Where materials are stored/used
Emergency Response/Contingency Plan What to do during an incident
Employee Training requirements Training approach and expectations
Recordkeeping requirements How records are kept

How an HMBP helps emergency responders

The HMBP helps emergency responders—especially the Fire Department—prepare for emergencies that could occur at the facility.

Key benefits include:
- responders can access the current chemical inventory
- responders can reach the emergency coordinator by phone 24 hours a day
- the plan provides the information needed for emergency responders to act effectively during a release or accident


Exemptions from HMBP reporting

Some businesses do not need to complete an HMBP if specific exemptions apply and they do not have other reportable hazardous materials.

Main exemptions listed for HMBP reporting

Exemption situation Details
Consumer products to the general public Contained solely in consumer products for direct distribution, less than 5 gallons, and not filled on-site
Certain medical professionals with gas Physician, dentist, podiatrist, veterinarian, or pharmacist storing oxygen, nitrogen, and/or nitrous oxide up to 1,000 cubic feet for each material
Lubricating oils (special limits) Store 55 gallons or less of any specific type of lubricating oil and total all lubricating oils does not exceed 275 gallons (used oil is excluded)
Propane for heating employee work areas Store no more than 300 gallons of propane used only to heat employee work areas
Small amounts of certain compressed gases Store less than 1,000 cubic feet of helium, argon, nitrogen, or xenon gas
Need the newest guidance Contact Environmental Programs for the latest information

How businesses can get the latest HMBP rules

Because exemptions and rules can change, businesses should use official local and state channels.

For the newest information, businesses are directed to contact Environmental Programs.


Diagram of how hazard planning connects to reporting

flowchart TD
A[Material used or stored] --> B[Check properties and quantity]
B --> C[Is it hazardous]
C --> D[Is it at or above reportable thresholds]
D --> E[Prepare or update HMBP]
E --> F[Annual review and recertify through CERS]
E --> G[Amend within 30 days if changes happen]
E --> H[Fire Department uses info during emergencies]

Summary

A material can be hazardous because of its physical properties, chemical characteristics, and sometimes infectious characteristics, especially when the quantity is large enough to create a real risk. In California, businesses that store or handle certain amounts must file an HMBP, and the process uses CERS (not paper). The plan’s goal is simple: make sure both the business and emergency responders can respond safely using the right inventory and contact information.