Despite the fact that salt is a commonly occurring compound, pure sodium chloride (NaCl) is much more difficult to come by. Because of its hygroscopic nature, which tends to make salt coagulate and solidify, most granulated salt has anti-caking agents added. However, the addition of these agents is prohibited by most salt spray test standards.
For example, the world's most popular salt spray test standard; ASTM B117, prohibits anti-caking agents, and also limits other impurities, as follows: total impurities < 0.3%, halides excluding chloride < 0.1%, copper < 0.3ppm - so the salt must be very pure indeed, with the limit for copper in particular set at an extremely low level. Other national and international test standards for corrosion testing are similarly demanding in their specifications.
To ensure compliance with the highest standards, Ascott has each batch of its Corro-Salt independently analysed by an UKAS* accredited laboratory, who use a combination of X-ray Fluorescence (XRF), Atomic Absorption Spectroscopy (AAS) and Fourier Transform Infrared (FTIR) to verify its purity.
*UKAS = United Kingdom Accreditation Service.
Each consignment of Corro-Salt purchased is supplied with an Ascott certificate of conformity and a copy of the UKAS laboratory analysis. Corro-Salt users can therefore rest assured that they will be testing in full compliance with the requirements of the most stringent standards.
Download the Corro-Salt brochure/datasheet.
Typical FTIR Graph
Typical Analysis of Corro-Salt
| Analysis by X-ray fluorescence | Total impurities | 0.145 % |
| Bromide | 0.008 % |
| Fluoride | none detected |
| Iodide | none detected |
| Analysis by atomic absorption | |
| Copper | 0.1 ppm |
| Analysis by Fourier transform infrared | |
| Organics | trace (< 1 ppm) |