Sodium Hypochlorite Standards for Commercial Bleach and On-Site Generated Bleach

Water utilities that use sodium hypochlorite for drinking water disinfection have the option of using bleach sourced from a chemical vendor (commercial bleach) or producing bleach on-site through use of a chemical generator.

Read on for a summary of the NSF/ANSI/CAN standards that apply under each option.

Chemicals, including hypochlorite bleach, which are transported to utilities for use in drinking water treatment fall under the scope of NSF/ANSI/CAN 60: Drinking Water Treatment Chemicals - Health Effects. Information on the NSF/ANSI/CAN testing and evaluation parameters for sodium hypochlorite products is contained in the 2016 edition of Municipal Water Matters. The NSF/ANSI/CAN 60 product certification listings for sodium hypochlorite products can be found by following the instructions below.

The NSF/ANSI/CAN 60 sodium hypochlorite certifications apply to the bleach products that appear in the NSF listings of each certified bleach production facility. Routine site audits and testing and evaluation of products from each facility take place in support of the NSF/ANSI/CAN 60 bleach product certifications.

Many water utilities manufacture sodium hypochlorite through on-site generators (in lieu of, or in addition to, purchased bleach). On-site generators, including hypochlorite bleach generators, fall under the scope of NSF/ANSI/CAN 61: Drinking Water System Components - Health Effects. The NSF/ANSI/CAN 61 product certification listings for chemical generators can be found by following the instructions below.

The associated footnotes shown in each of the chemical generator listings designate the effluent chemical produced from the certified generator (for example, sodium hypochlorite for bleach generators).

The NSF/ANSI/CAN 61 chemical generator certifications apply to the generators that appear in the NSF listings of each certified facility. Routine site audits of the generator assembly facility are conducted, and testing and evaluation of the effluent chemical from a representative generator take place in support of the NSF/ANSI/CAN 61 chemical generator certifications. The effluent chemical sample used for product analysis is prepared by NSF after operating the generator in accordance with the manufacturer’s published instructions.

It is important for on-site producers of treatment chemicals to follow the manufacturer’s use instructions closely, to ensure that the effluent chemical produced meets established specifications. One key component of the manufacturer’s use instructions is the designated feed stock chemical(s) that is specified for use in the certified generator. For example, many sodium hypochlorite generator instructions specify that an NSF/ANSI/CAN 60-certified salt should be used as the generator feed stock. The NSF/ANSI/CAN 60 product certification listings for sodium chloride salt can be found by following the instructions below.

The certification listings for salt products that have been certified for electrochlorination end use have a footnote in their listings stating, “Certified for use in the electrochlorination process for on-site disinfectant generators.” In addition, the listing footnotes specify the maximum disinfectant feed concentration of the salt that has been established as part of the use restrictions of the salt product. If you have questions about certified bleach products, please contact NSF’s consumer and regulatory hotline at +1 800 673 8010 or [email protected].