Glossary
P
Vehicles that meet the ARB super ultra low emissions standard, have zero evaporative emissions and have a 15 year/150,000 mile warranty. See our Drive Clean website.
Any material, except pure water, that exists in the solid or liquid state in the atmosphere. The size of particulate matter can vary from coarse, wind-blown dust particles to fine particle combustion products. For more information, see ARB's PM brochure.
A level of airborne pollutants that is much higher than average. They can occur over a short period of minutes or hours in response to sudden releases, or they can occur due to a longer term build-up over several days.
The substance with the chemical formula 'C2Cl4,' also known by the name 'tetrachloroethylene' which has been identified by the ARB and listed as a toxic air contaminant (title 17, California Code of Regulations, section 93000).
Regulation requiring fleet owners of two or more heavy-duty diesel powered trucks or buses to perform annual smoke opacity inspections on each vehicle's engine that is four years old or older. Engines that exceed opacity standards must be repaired to be brought into compliance. Fleet owners must keep records of the annual smoke test for two years and make these records available to ARB upon request.
Written authorization from a government agency (e.g., an air quality management district) that allows for the construction and/or operation of an emissions generating facility or its equipment within certain specified limits. For more information, visit our permitting activities portal page.
An operational permit issued yearly by an air district to sources that meet specified regulations.
A group of compounds formed from the photochemical reactions of nitrogen and organic compounds. PANs are components of smog and known to cause eye irritation.
Refers to the length of time a compound stays in the atmosphere, once introduced. A compound may persist for less than a second or indefinitely.