Document ID: chunk:federal_register_of_legislation:F2025C00151:body:0:p4
Version: federal_register_of_legislation:F2025C00151
Segment Type: other
Provision Reference: 
Character Range: 11591–14656

with:
 (a) the formula C5H6BrClN2O2; and
 (b) the formula weight 241.5.
 (2) For bromo-chloro-dimethylhydantoin, the chemical specifications are the following:
 (a) appearance—solid or free flowing granules;
 (b) colour—white:
 (c) odour—faint halogenous odour;
 (d) melting point—163–164ºC;
 (e) specific gravity—1.8–2;
 (f) solubility in water—0.2 g/100 g at 25ºC;
 (g) stability—stable when dry and uncontaminated.
 (3) Bromo-chloro-dimethylhydantoin must be manufactured in accordance with the following process:
 (a) solid dimethylhydantoin (DMH) must be dissolved in water with bromine and chlorine;
 (b) the reaction must be 0.5 mole bromine and 1.5 mole chlorine for one mole DMH;
 (c) during the reaction the pH must be kept basic by the addition of caustic soda;
 (d) the wet product must be transferred to a drier where it is dried to a powder at low temperature;
 (e) the powder may then be tableted or granulated.
 (4) Bromo-chloro-dimethylhydantoin may be assayed in accordance with various analytical methods, including GLC, HPLC, UV and NMR.
 Note HPLC offers the best sensitivity.
S3—9 Specification for carboxymethyl cellulose ion exchange resin
 (1) This specification relates to regenerated cellulose that has been cross-linked and alkylated with epichlorohydrin and propylene oxide, then derivatised with carboxymethyl groups, as a result of which the amount of epichlorohydrin plus propylene oxide is no more than 70% by weight of the starting amount of cellulose.
 (2) When subjected to the extraction regime listed in the 21 CFR § 173.25(c)(4), but using dilute hydrochloric acid at pH 2 in place of 5% acetic acid, the ion exchange resins shall result in no more than 25 ppm of organic extractives.
S3—10 Specification for dibromo-dimethylhydantoin
 (1) In this section:
dibromo-dimethylhydantoin means the chemical with CAS Number 77-48-5 and formula C5H6Br2N2O2.
 (2) For dibromo-dimethylhydantoin, the specifications (which relate to purity) are the following:
 (a) dibromo-dimethylhydantoin—no less than 97%;
 (b) sodium bromide—no more than 2%;
 (c) water—no more than 1%.
S3—11 Specification for diethyl aminoethyl cellulose ion exchange resin
 (1) This specification relates to:
 (a) regenerated cellulose, cross-linked and alkylated with epichlorohydrin and propylene oxide, then derivatised with tertiary amine groups whereby the amount of epichlorohydrin plus propylene oxide is no more than 70% by weight of the starting amount of cellulose; and
 (b) regenerated cellulose, cross-linked and alkylated with epichlorohydrin then derivatised with tertiary amine groups whereby the amount of epichlorohydrin is no more than 10% by weight of the starting amount of cellulose.
 (2) When subjected to the extraction regime listed in the 21 CFR § 173.25(c)(4), but using dilute hydrochloric acid at pH 2 in place of 5% acetic acid, the ion exchange resins shall result in no more than 25 ppm of organic extractives.
S3—12 Specification for dimethyl ether
  For dimethyl ether, the specifications are the following:
 (a) purity—minimum of