27 C.F.R. § 21.96

(a) Alkalinity. Strongly alkaline to litmus.

(b) Ammonia content. 27 to 30 percent by weight. Accurately weigh a glass-stoppered flask containing 25 mL of water, add about 2 mL of the sample, stopper, and weigh again. Add methyl red indicator, and titrate with 1 N sulfuric acid. Each mL of 1 N sulfuric acid is equivalent to 17.03 mg of NH3

(c) Color. Colorless liquid.

(d) Non-volatile residue. 2 mg maximum. Dilute a portion of the sample with 1 1/2 times its volume of distilled water. Evaporate 10 mL of this product to dryness in a tared platinum or porcelain dish. Dry residue at 105 °C. for 1 hour, cool and weigh.

(e) Odor. Characteristic (exceedingly pungent).

(f) Specific gravity at 20 °/4 °C. 0.8920 to 0.9010.