Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is a standard which provides detailed criteria for the hazardous effects of chemicals using specific labeling and safety data sheets defined by hazard class and category. Its main goal is to improve safety and health of workers by enabling employers, workers, health professionals, and emergency responders to have more efficient and effective access to information.

A Hazard classification proposal according to GHS criteria must include brief statements for each health hazard class and details for all the available scientific evidence. The proposed classification refers to the acute toxicity and the corrosivity of the material and it is based on animal tests.

The proposal starts with the identification of the substance, where the manufacturer provides the EINECS or IUPAC name and the CAS number. Then he must give the molecular and structural formula, purity (w/w), any significant impurities and known uses.

The second part contains the physicochemical characteristics, like physical form, molecular weight, melting and boiling points, relative and vapor density, water solubility, vapor pressure, flammability, explosivity, oxidizing properties etc.

The third part presents the health and environmental characteristics for acute toxicity, skin and eye irritation, skin and respiratory sensitization, specific target organ toxicity, carcinogenicity, germ cell mutagenicity, reproductive toxicity and fertility. The manufacturer must demonstrate all available scientific studies with details. In the report must be mentioned the species of the used animals (rats, rabbits), the lethal dose (LD) or concentration (LC), the exposure time and the most significant observations.

According to OSHA estimations classifying chemical hazards and revising safety data sheets and labels to meet GHS requirements will cost approximately $22.5 million a year on an annualized basis. However, more than 45 million employees who could be exposed to hazardous chemicals will benefit from this change.