Environmental consultants send water samples to analytical laboratories, and the samples are commonly acidified to a pH below 2 with nitric acid as a preservative for trace metals. A letter writer asked whether a manufacturer may list the physical and chemical properties of the concentrated chemical (68% nitric acid) in SDS Section 9, with a note about the actual percentage, when the product actually contains only about 5% nitric acid.
OSHA answered no. The Hazard Communication Standard requires the SDS to give the physical and chemical properties of the hazardous chemical as it exists — properties must reflect the empirical data of the actual substance or mixture, based on observations or tests performed on the chemical (29 CFR 1910.1200). Concentrated 68% nitric acid has different properties than a 5% acidified water sample, so using the concentrated data would be inaccurate.
OSHA also reminded the industry that environmental consultants, acting as manufacturers or importers, must properly label samples and provide an accurate SDS so correct hazard information flows downstream. For hard-to-find data, OSHA pointed to the Occupational Chemical Database, the CRC Handbook, the OECD eChem Portal, and trade associations. Where information is unavailable or irrelevant, Section 9 must include a note stating that.