Toxicological evaluations performed as part of the certification process ensure that products do not contribute unsafe levels of contaminants to food, water or air. Toxicological evaluations involve preparing and exposing a product in the laboratory in a manner consistent with its intended use. Plastic pipe, for example, would be exposed to both acidic and basic water during a conditioning period. The lab then tests the extraction water for metals and organic compounds. After reviewing the product formulation to determine which contaminants may migrate or extract, NSF performs specific analytical tests on the extraction waters and compares the levels of chemical extraction to established safe levels.
Certification is recommended only for products whose extractants are within the allowable levels.
Toxicological evaluation considers not only a product's chemical formulation, but also its residual ingredients, reaction byproducts, and contaminants from the manufacturing process. Knowing levels of chemicals that are safe for human exposure, NSF toxicologists distinguish between products that protect public safety and those that do not. By certifying products through NSF, a manufacturer demonstrates responsible product stewardship through a commitment to preserving public health and safety and protecting the environment. For manufacturers, recognition as a steward of public health is one of many benefits of certification. Others include regulatory acceptance of certified products, name recognition with credibility, and elimination of the need for multiple regulatory reviews.