Mixture

Under hazard communication rules, mixtures are classified either by testing the mixture itself or by using the data on its ingredients along with set calculation methods. That is why a product can be classified as hazardous even when no single ingredient looks alarming on its own, or the reverse.

Unlike a Substance, a mixture has no single CAS number. The SDS lists the hazardous components in Section 3, usually with concentration ranges instead of exact values. Suppliers can sometimes withhold an exact percentage or an identity under trade secret rules, but not information needed to handle the product safely.

When you read a mixture's sheet, the classification, signal word, and hazard statements apply to the product as supplied. A cleaning concentrate and its diluted solution can have different hazards, so check whether the sheet covers the form you use.

Mixtures can also create hazards from interaction. Mixing two products yourself can produce a new substance and a new risk, and the sheet for each one only covers the product as supplied. Incompatibilities listed on the sheet can help avoid this.

Some solid objects with no release of chemicals in use are articles, not mixtures.