California Code, Health and Safety Code - HSC § 25201.12

Notwithstanding any other provision of law, a hazardous waste facilities permit or other grant of authorization from the department, and payment of any fee imposed pursuant to Article 9.1 (commencing with Section 25205.1), are not required for a facility, with regard to the facility's operation of a physical process to remove air pollutants from exhaust gases prior to their emission to the atmosphere, as permitted by an air pollution control district or an air quality management district, unless a permit is required for that operation pursuant to the federal act. However, the facility is subject to all requirements imposed pursuant to this chapter on hazardous waste generators with regard to any liquid, semisolid, or solid hazardous waste that is generated as part of, and upon its removal from, the air pollution control process.