1. (a) A threshold quantity of a regulated substance is present at a stationary source if the total quantity of a regulated substance contained in a process exceeds the threshold listed in Section 5130.6.

2. (b) For the purpose of determining whether more than a threshold quantity of a regulated substance is present at the stationary source, the following apply:

   1. (1) Concentrations of a regulated toxic substance in a mixture:

      1. (A) A mixture of less than one percent by weight of a regulated toxic substance need not be considered when determining whether more than a threshold quantity is present at the stationary source. A mixture containing a regulated toxic substance is regulated if the concentration of the toxic substance present in the mixture is one percent or greater by weight. The owner or operator of a stationary source shall only consider the weight of the regulated substance in the mixture, not the entire weight of the mixture.
      2. (B) The owner or operator of a stationary source, when determining whether more than a threshold quantity of a regulated toxic substance in a mixture (one percent or greater by weight, pursuant to (A)) is present at the stationary source, need not consider portions of the process which can be demonstrated to have a partial pressure of the regulated substance in the mixture (solution), under the handling or storage conditions, which is less than 10 millimeters of mercury (mm Hg). The owner or operator of the stationary source shall document any exempted portions of processes where the partial pressure measurements or estimates are less than 10 mm Hg.

      3. (C) The exemption regarding 10 mm Hg of partial pressure in (B) does not apply to:

         1. (i) Regulated substances which are solids as noted in Section 5130.6, Table 3;
         2. (ii) Those regulated substances that failed the evaluation pursuant to Section 25532(i)(2) of HSC as noted in Section 5130.5, Table 3; or,
         3. (iii) Oleum, toluene 2,4-diisocyanate, toluene 2,6-diisocyanate and toluene diisocyanate (unspecified isomer) as noted in Section 5130.6.

   2. (2) Concentrations of a regulated flammable substance in a mixture. A mixture of less than one percent by weight of a regulated flammable substance need not be considered when determining whether more than a threshold quantity is present at the stationary source. Except as provided in Sections (b)(2)(A) and (2)(B) of this section, if the concentration of the substance in the mixture is one percent or greater by weight of the mixture, then, for the purpose of determining whether a threshold quantity is present at the stationary source, the entire weight of the mixture shall be treated as the regulated substance unless the owner or operator can demonstrate that the mixture itself does not have a NFPA flammability hazard rating of 4. The demonstration shall be in accordance with the definition of flammability hazard rating 4 in the NFPA 704, Standard System for the Identification of the Hazards of Materials for Emergency Response, NFPA, Quincy, MA, 1996. (Available from the NFPA, 1 Batterymarch Park, Quincy, MA 02269-9101. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552 (a) and 1 CFR part 51. Copies may be inspected at the Environmental Protection Agency Air Docket (6102), Attn: Docket No. A-96-08, Waterside Mall, 401 M. St. SW., Washington D.C.; or at the Office of Federal Register at 800 North Capitol St., NW, Suite 700, Washington, D.C.) Boiling point and flash point shall be defined and determined in accordance with NFPA 30, Flammable and Combustible Liquids Code, NFPA, Quincy, MA, 1996. (Available from the NFPA, 1 Batterymarch Park, Quincy, MA 02269-9101. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552 (a) and 1 CFR part 51. Copies may be inspected at the Environmental Protection Agency Air Docket (6102), Attn: Docket No. A-96-08, Waterside Mall, 401 M. St. SW., Washington D.C.; or at the Office of Federal Register at 800 North Capitol St., NW, Suite 700, Washington, D.C.) The owner or operator shall document the NFPA flammability hazard rating.

      1. (A) Gasoline. Regulated substances in gasoline, when in distribution or related storage for use as fuel for internal combustion engines, need not be considered when determining whether more than a threshold quantity is present at a stationary source.
      2. (B) Naturally occurring hydrocarbon mixtures. Prior to entry into a natural gas processing plant or a petroleum refining process unit, regulated substances in naturally occurring hydrocarbon mixtures need not be considered when determining whether more than a threshold quantity is present at a stationary source. Naturally occurring hydrocarbon mixtures include any combination of the following: condensate, crude oil, field gas, and produced water, each as defined in Section 5050.3.
   3. (3) Articles. Regulated substances contained in articles need not be considered when determining whether more than a threshold quantity is present at the stationary source.

   4. (4) Uses. Regulated substances, when in use for the following purposes, need not be included in determining whether more than a threshold quantity is present at the stationary source:

      1. (A) Use as a structural component of the stationary source;
      2. (B) Use of products for routine janitorial maintenance;
      3. (C) Use by employees of foods, drugs, cosmetics, or other personal items containing the regulated substance; and,
      4. (D) Use of regulated substances present in process water or non-contact cooling water as drawn from the environment or municipal sources, or use of regulated substances present in air used either as compressed air or as part of combustion.

   5. (5) Activities in laboratories. If a regulated substance is manufactured, processed, or used in a laboratory at a stationary source under the supervision of a technically qualified individual as defined in Section 720.3(ee) of Chapter 1 of Title 40 of CFR, the quantity of the substance need not be considered in determining whether a threshold quantity is present. This exemption does not apply to:

      1. (A) Specialty chemical production;
      2. (B) Manufacture, processing, or use of substances in pilot plant scale operations; and,
      3. (C) Activities conducted outside the laboratory.

Note: Authority cited: Sections 25531 and 25534.05, Health and Safety Code. Reference: Sections 25532(l), 25532(n) and 25543.3, Health and Safety Code; and Section 68.115, Part 68, Title 40, Code of Federal Regulations.

History

1. Change without regulatory effect renumbering section 2770.2 to new section 5130.2, including amendment of subsections (a), (b)(1)(C)(i)-(iii) and (b)(2)(B), filed 3-6-2024 (Register 2024, No. 10).