1.1 This specification covers the general, physical, chemical and performance requirements for Supplemental Coolant Additives (SCAs) at a precharged level in the cooling systems of heavy-duty engines. Note 1-After precharging, SCAs are customarily used to periodically service cooling systems at 1/4 to 1/3 the precharged dosage, in order to compensate for additives lost through dilution and depletion. 1.2 The SCA products meeting this specification are intended for use with water or recommended dilutions of coolant concentrates, or prediluted engine coolants. Engine coolant products shall be of the low-silicate type Specification D4985, or Specification D5345, if ethylene glycol based. Propylene glycol base low-silicate-type coolant products may also be used, if these materials meet the chemical and performance requirements of Specification D4985 or Specification D5345. 1.3 The SCA concentrate before dissolution may be in either liquid, solid, or slurry form. The form is as agreed upon between the manufacturer and the user. 1.4 The values stated in SI units are to be regarded as standard. The inch-pound units in parentheses are approximate equivalents provided for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Note 2.