The laws and regulations regarding the sale, purchase, and use of natural gas vehicles (NGV) differ from state to state. It is important to understand the specific laws and regulations for the states in which you own and operate an NGV. Important issues to understand include certification requirements, the way in which natural gas motor fuel is taxed, and the numerous incentives available for the purchase or conversion of an NGV or for the construction of related infrastructure.
Certification Requirements: EPA vs. CARB
U.S. Environmental Protection Agency (EPA) regulations require manufacturers of alternative fuel systems, whether original equipment manufacturer (OEM) or aftermarket conversion systems, to prove that their systems continue to meet emission requirements and do not increase emissions beyond the levels originally prescribed for the vehicle undergoing modification. Most states recognize EPA certified systems. However, California was given special permission to establish its own certification rules for alternative fuel systems through the California Air Resources Board (CARB), which other states have the option of adopting over those of EPA. In regards to converted or upfitted vehicles, CARB states must also undergo the additional step and adopt California rules for aftermarket systems (13 CCR 2030) in order to require aftermarket conversions to be CARB-certified in their state. As such, NGVAmerica does not believe there is any basis for requiring aftermarket conversions to be CARB certified if the state has not also adopted California rules for aftermarket systems. In such cases, EPA systems should be satisfactory.
In March 2011, EPA issued new rules for aftermarket conversion systems. The new rules expand compliance options to include less burdensome demonstration requirements for vehicles. Until September 2013, CARB certification requirements had not been updated since 1995 and were essentially obsolete. Complying with CARB rules were very costly and time consuming, especially for bi-fuel vehicles. The new rules streamline the certification requirements and provide additional flexibility for companies certifying natural gas conversion systems. However, CARB rules for aftermarket systems remain more burdensome than those of EPA.
Below is a map showing EPA states (blue) and CARB states (red). All CARB states require CARB approved OEM systems. However, most CARB states do not require CARB approved aftermarket systems and will accept those approved by EPA.
For Aftermarket Adoption in Washington and Oregon (as in the case of the ZHRO™ Fuel Injector System), regulations appear to allow for EPA approved systems.
The information contained herein has been taken from the NGVAmerica website.