1.1 This specification covers requirements for first grade concentrated natural rubber latex (see Table 1) of the following types: Type 1-Centrifuged natural latex preserved with ammonia only or by formaldehyde followed by ammonia. Type 2-Creamed natural latex preserved with ammonia only or by formaldehyde followed by ammonia. Type 3-Centrifuged natural latex preserved with low ammonia with other necessary preservatives. 1.2 This specification is not necessarily applicable to latices prepared or preserved by other methods, and shall not be construed as limiting the desirability or usefulness of other types of latices. It does not apply to natural latex sources other than Hevea braziliensisnor to compounded latex concentrates. 1.3 The analytical procedures applicable to the specifications are included and appear in the following order: Section Sampling 6 and 7 Total Solids 8 Dry Rubber Content 9 Total Alkalinity 10 Viscosity 11 Sludge Content 12 Coagulum Content 13 KOH Number 14 pH 15 Mechanical Stability 16 Copper and Manganese 17 Density 18-30 Volatile Fatty Acids 31-35 Boric Acid 36 Dry Films 37 Precision for All Test Methods 38 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.