This website contains information and resources on Comprehensibility Testing for the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Comprehensibility testing is a survey based method for obtaining information on the understanding of GHS hazard communication elements among the public.

"Comprehensibility" refers to the ability of an individual reading a label, warning, or safety data sheet to understand the information sufficiently to take the appropriate precautionary measures. Comprehensibility testing is therefore a key tool for assessing the effectiveness of chemical hazard communication pictograms and/or key statements and provides important feedback for developing a chemical hazard communication system and targeted training. The results of comprehensibility testing can help identify areas where capacity building interventions are needed in order to improve understanding of GHS-based hazard communication elements, thereby improving protection of human health and the environment.

This rapid comprehensibility testing package has been developed by the Occupational and Environmental Health Research Unit (OEHRU) in the School of Public Health and Family Medicine at the University of Cape Town in South Africa, in collaboration with the United Nations Institute for Training and Research (UNITAR) and with support from the Government of Switzerland and the European Union.