Nickel

Nickel (CAS 7440-02-0) is a transition metal used as the primary active anti-seize component in nickel-based anti-seize compounds. Nickel flakes provide superior corrosion and galling protection specifically on stainless steel, titanium, and nickel-alloy fasteners — the applications where copper-based anti-seize is contraindicated due to stress-corrosion cracking risk. The nickel formula is also recommended for applications where copper contamination must be avoided, including food-processing equipment and certain aerospace applications.

Nickel is a documented skin sensitizer (GHS H317, Cat 1). Individuals with known nickel sensitivity — common in those with reactions to metal jewelry — face allergic contact dermatitis risk from skin contact. Nitrile gloves are the standard precaution for nickel-containing products.

At ingredient level, nickel compounds carry carcinogenicity classifications (H350 at mixture level in some formulations) based on occupational epidemiology from nickel refinery workers and metalworking environments involving high concentrations of nickel particulate. In paste format bound in a petroleum-grease carrier, the respirable particulate pathway that drives the occupational carcinogen classification is not present under typical consumer application conditions (applying paste to a few fasteners per session). California Proposition 65 requires disclosure of nickel as a carcinogen.

Nickel is a CWA Priority Pollutant and is persistent in aquatic environments. Waste paste containing nickel flake should be disposed of as automotive hazardous waste.