Due to the hazardous nature of calcium hypochlorite, no more than three 6 oz.
bottles of the material will be carried onboard Army watercraft.
Special storage requirements for calcium hypochlorite are necessary to eliminate
the potential fire hazard. Calcium hypochlorite should be stored in a cool, dry
area outside of engineering or machinery spaces, flammable storerooms, or with
(2) In contrast to calcium hypochlorite, sodium hypochlorite liquid may be stored in ge neral
15. Free Available Chlorine
a. Use of the below test kit is required to provide daily assurance that the vessel's potable water
system contains the required amount of disinfect ing agent.
b. The following kit, which is available through the federal supply system, is authorized for use
onboard Army watercraft:
(1) Comparator, Color, NSN 6630-01-067-3827 (also referred to as the DPD Test Kit), for free
chlorine /total bromine detection. Set detects chlorine in the range of 0.1 to 10.0 ppm, pH in
the range of 6.8 to 8.2, and bromine in the range of 0.2 to 22.2 ppm. Kit uses the diethyl-p-
phenylenediamine (DPD) test method.
(3) For replacement Chlorine Test Tablets, order NSN 6810-01-044-0315.
a. Free available chlor ine testing for the presence of FAC residual in the potable water system is the
most practical means of ensuring a safe water supply on Army watercraft. However, a more definitive
means of ensuring a safe water supply is performing a bacteriological analysis.
b. The conduct of laboratory analyses is beyond the capability of watercraft personnel. Samples must
be submitted to a local medical facility for testing. Samples will be submitted at a frequency
determined by the Director of Health Services. The shore medical facility is responsible for providing
sterile containers and performing the bacteriological analysis. A record of sample results will be
maintained by the watercraft.