Our nylon fittings are made with FDA approved high-quality first-generation resin and are NSF 61 certified. They are generally acceptable for use at working pressures up to 150 psi and will withstand temperatures as high as 75°C (167°F) and as low as -40°C (-40°F) although they should not be used below 0°C (32°F) where fluid expansion from freezing can occur. Nylon is a strong, abrasion-resistant material with excellent impact resistance. Nylon has good chemical resistance to organic solvents, oils, and fuels but is not recommended for use with strong acids and bases such as ammonium, boric acid, calcium, or sulfuric acid.