Sodium Chloride.

Yes — sodium chloride (NaCl) is the chemical name and rock salt is the trade name for the same product. Both refer to mined or solar-evaporated sodium chloride at 95–99 % purity, screened to gradation between 6.3 mm and 12.5 mm for highway and commercial de-icing. Municipal procurement documents, MSDS sheets, and environmental impact assessments use "sodium chloride" because it is the precise chemical name. Contractor and retail markets use "rock salt" because it is the trade language. Functionally the products are identical — same source mines, same gradation standards, same effective temperature range, same application rates. The two product pages on our catalog exist because search behaviour and procurement language split between the two terms.

Sodium chloride (NaCl) is the most economical chloride de-icer, effective to –10 °C, and the basis for almost all commercial winter operations. Calcium chloride (CaCl2) is the strongest chloride de-icer, effective to –32 °C, exothermic on contact, and costs 3–5x more per tonne. Magnesium chloride (MgCl2) sits between sodium and calcium chloride on temperature range and price, is less corrosive than calcium chloride, and is the environmentally preferred chloride. Potassium chloride (KCl) is mostly used in pet-safe and landscape-sensitive blends because it is less harmful to vegetation — it is not used as a primary de-icer because of cost and lower melt performance. For routine Canadian de-icing above –10 °C, sodium chloride is the right choice on cost and performance.

Sodium chloride applied at commercial rates does load chloride into adjacent soils, surface water, and shallow groundwater. Environment Canada has documented chloride concentrations in winter and spring meltwater discharge from urban areas at 1,000–5,000 mg/L — well above the chronic-toxicity threshold for freshwater aquatic life (120 mg/L). Mitigation strategies include calibrated spreaders (cuts application 25–40 %), pre-wetting (cuts application 20–35 %), application only when pavement temperature allows effective melt (rock salt is wasted below –10 °C), and switching to magnesium chloride or potassium acetate for environmentally sensitive sites. Total chloride loading from municipal road salt remains the dominant pathway for winter chloride contamination of Canadian surface water.

Municipal sodium chloride contracts run on annual or multi-year supply agreements with one of the three major Canadian sources — Compass Minerals (Goderich, Ontario), K+S Windsor Salt, or Cargill. Specifications follow AMS‑2014 (American Public Works Association) or ASTM D632, with minimum 95 % NaCl purity, gradation between 6.3 mm and 12.5 mm, moisture below 1 % at delivery, and lot-traceability documentation. Delivery is by bulk truck (typically 20–40 tonnes per load) to municipal salt domes, with cumulative seasonal volumes ranging from 200 tonnes for small municipalities to 200,000+ tonnes for the City of Toronto. Pricing is locked at contract signing (typically July–September for the following winter) and indexed to mine-gate price plus delivery.

Material Safety Data Sheets (MSDS) for de-icing sodium chloride are published by each manufacturer — Compass Minerals, K+S Windsor Salt, and Cargill all maintain current SDS documents on their corporate websites. The hazards of de-icing sodium chloride are low: it is non-flammable, non-explosive, and rated mild for skin and eye irritation. Ingestion of large quantities can cause sodium toxicity. Environmental hazard is rated moderate-to-high because of chloride loading on freshwater. We provide the current MSDS with every commercial shipment and on request for procurement documentation.