1.1This specification covers requirements for first grade concentrated natural rubber latex (see Table 1) of the following categories:
Category 1—Centrifuged Hevea natural latex preserved with ammonia only or by formaldehyde followed by ammonia.
Category 2—Creamed Hevea natural latex preserved with ammonia only or by formaldehyde followed by ammonia.
Category 3—Centrifuged Hevea natural latex preserved with low ammonia with other necessary preservatives.
Category 4—Centrifuged, or centrifuged and creamed, guayule latex, or other natural rubber latex, containing less than 200 µg total protein per gram dry weight of latex, with ammonia or other hydroxide, with other necessary preservatives and stabilizers.
Category 5—Centrifuged Hevea natural latex treated with aluminum hydroxide or by other means, preserved with ammonia only or by formaldehyde followed by ammonia containing less than 0.5 % non-rubber content.
1.2This 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 categories of latices. It does apply to natural latex sources other than Hevea brasiliensis but does not apply to compounded latex concentrates.
1.3The 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 |
| Protein Content | 10 |
| Total Alkalinity | 11 |
| Viscosity | 12 |
| Sludge Content | 13 |
| Coagulum Content | 14 |
| KOH Number | 15 |
| pH | 16 |
| Mechanical Stability | 17 |
| Copper and Manganese | 18 |
| Density | 19 – 31 |
| Volatile Fatty Acids | 32 – 36 |
| Boric Acid | 37 |
| Dry Films | 38 |
| Precision for All Test Methods | 39 |
1.4The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.