14 C.F.R. § 420.66
(a) Separation of energetic liquids and determination of distances. A launch site operator must separate each explosive hazard facility from each other explosive hazard facility, each public area, and each public traffic route in accordance with the minimum separation distance determined under this section for each explosive hazard facility storing:
(4) Any energetic liquid that is:
(b) Quantity. For each explosive hazard facility, a launch site operator must determine the total quantity of all energetic liquids in paragraph (a)(1) through (4) of this section as follows:
(1) The quantity of energetic liquid in a tank, drum, cylinder, or other container is the net weight in pounds of the energetic liquid in the container. The determination of quantity must include any energetic liquid in associated piping to any point where positive means exist for:
(2) A launch site operator must convert the quantity of each energetic liquid from gallons to pounds using the conversion factors provided in table E-6 of appendix E of this part and the following equation:
Pounds of energetic liquid = gallons × density of energetic liquid (pounds per gallon).
(3) Where two or more containers of compatible energetic liquids are stored in the same explosive hazard facility, the total quantity of energetic liquids is the total quantity of energetic liquids in all containers, unless:
(c) Determination of separation distances for compatible energetic liquids. A launch site operator must determine separation distances for compatible energetic liquids as follows:
(1) To determine each intraline, public area, and public traffic route distance, a launch site operator must use the following tables in appendix E of this part:
(d) Determination of separation distances for incompatible energetic liquids. If incompatible energetic liquids are stored within an intraline distance of each other, a launch site operator must determine the explosive equivalent in pounds of the combined liquids as provided by paragraph (d)(2) of this section unless intervening barriers prevent mixing.
[Doc. No. FAA-2011-0105, 77 FR 55114, Sept. 7, 2012]