What is a CARB and how does it differ from a carburetor?
Before diving into the regulatory bodies, it's crucial to clarify the term “carb.” While often confused in conversation, the term can refer to two very different things: the California Air Resources Board (CARB) and a carburetor, a mechanical device. A carburetor is an engine part that mixes air and fuel for combustion and has largely been replaced by fuel injection in modern vehicles. CARB, on the other hand, is a government agency that sets emissions regulations. This article will focus on CARB as a regulatory body in comparison to the EPA.
The Environmental Protection Agency (EPA)
The EPA is a federal agency established in 1970 to protect human health and the environment nationwide. It is responsible for setting nationwide emissions standards for all internal combustion engines, including those in cars, trucks, heavy equipment, and generators manufactured or sold in the United States. All products sold in the U.S. must meet EPA regulations at a minimum. The EPA issues certificates of conformity to manufacturers who demonstrate compliance through testing.
The California Air Resources Board (CARB)
CARB is a state-level agency in California with a mission to promote and protect public health through effective reduction of air pollutants. Established in the 1960s to combat California's severe smog problem, CARB is unique in that it is permitted to set and enforce its own emissions standards, which are often significantly stricter than the federal EPA standards. Because of California's size and influence, its regulations often drive nationwide innovation in cleaner technologies. Products sold in California must be CARB-certified in addition to meeting EPA requirements.
The impact of CARB regulations across the U.S.
CARB's influence extends far beyond California's borders. Under the Clean Air Act, other states can choose to adopt California's emissions standards. These are known as "CARB states." As of 2025, many states have followed California’s lead, particularly concerning light-duty and heavy-duty vehicle regulations. If you reside in or plan to operate a vehicle or equipment in one of these states, you must comply with CARB standards, which typically requires CARB-certified products.
Practical differences for consumers and mechanics
- Catalytic Converters: CARB-compliant catalytic converters are built to stricter standards and often contain a higher concentration of precious metals, leading to longer warranties compared to their EPA-compliant counterparts. Installing an EPA-only cat on a CARB-compliant vehicle is illegal. CARB-compliant converters are stamped with an Executive Order (EO) number.
- Engine Certification: You can check your Vehicle Emissions Control Information (VECI) label, typically under the hood, to determine if your vehicle meets CARB standards. If the label mentions California, ARB, or LEV (Low Emission Vehicle), the vehicle is CARB-certified.
- Generators and Small Engines: For power equipment like generators, a CARB-compliant model releases fewer harmful emissions and particulates. While all generators sold in the U.S. must meet EPA standards, those sold in California must also meet CARB's stricter requirements.
EPA vs. CARB: A detailed comparison
| Feature | Environmental Protection Agency (EPA) | California Air Resources Board (CARB) |
|---|---|---|
| Jurisdiction | Federal (Nationwide) | California State (and states that adopt CARB rules) |
| Regulatory Power | Sets minimum nationwide emissions standards | Sets more stringent emissions standards for California |
| Stringency | Less strict than CARB standards | Often stricter and more elaborate than EPA standards |
| Compliance | Required for all new vehicles and engines in the U.S. | Required for all new vehicles and engines sold in CARB states, in addition to EPA rules |
| Product Versions | Some manufacturers may produce separate, less expensive EPA-only versions | Products sold in California must meet CARB standards; often sold as "50-state legal" |
| Enforcement | Oversees nationwide compliance | Enforces compliance within California and CARB states |
| Focus | Regulates broad categories of pollutants across various mobile sources | More aggressive approach, with stronger focus on reducing smog and greenhouse gases |
A list of key CARB states
States that have adopted California's stricter emissions standards include, but are not limited to:
- Colorado
- Connecticut
- Delaware
- Maine
- Maryland
- Massachusetts
- New Jersey
- New York
- Oregon
- Pennsylvania
- Rhode Island
- Vermont
- Washington
- Virginia
It is always wise to check current regulations as the list of adopting states can change.
Conclusion
Understanding the difference between the federal EPA and California's CARB is essential for anyone purchasing or working with vehicles and engines. While all products must meet EPA's baseline federal standards, those sold or operated in California and other CARB-adopting states must also adhere to CARB's stricter regulations. These rules drive manufacturers to produce cleaner, more durable equipment, with a key example being the difference in catalytic converters. For consumers and mechanics, recognizing the certification standard is critical for compliance and proper equipment selection. The continued push for cleaner air means this dual-agency approach to emissions standards will likely remain a significant factor in the automotive and equipment industries for the foreseeable future.
For more detailed information on California's emissions programs, visit the California Air Resources Board official website.
