The GHS hazard classifications are based on a weight-of-evidence (WoE) evaluation of the currently available data for the two forms of copper metal. When data were not available for a particular endpoint, a read-across approach was applied in which experimental data were extrapolated from other copper forms and compounds.

Toxicological information was primarily obtained from comprehensive assessments and regulatory documents, such as:

• the Chemical Safety Report for Copper (ECI, 2018),
• the Harmonized Classification and Labeling (CLH) Report for Granulated Copper (ANSES, 2017),
• the CLH Report for Copper Flakes (coated with aliphatic acid) (ANSES, 2013),
• and the European Union Voluntary Risk Assessment for Copper (ECI, 2008),

and supplemented with information in:

• the Organization for Economic Co-operation and Development (OECD) Screening Information Dataset 2010 “Initial Assessment Profile and Initial Assessment Report on Copper and Copper Compounds” (OECD, 2010) and 2014 “Initial Assessment Profile Report on Copper and Copper Compounds” (OECD, 2014);
• the European Chemicals Agency (ECHA) Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) registration document for copper (ECHA, 2018);
• and the available scientific literature.

Based on all the available information, the resulting GHS human health and environmental hazard classifications for the two forms of copper metal evaluated are summarized in Table ES.1 of the report. If a classification for a specific chemical, physical, or toxicological endpoint is not listed below, then the WoE suggests that no hazard classification is necessary.

Table ES.1  Summary of GHS Hazard Classifications for Copper Metal

Copper Metal Form	GHS Hazard Classifications
Copper Massive CAS: 7440-50-8, EC: 231-159-6	Acute Aquatic Toxicity Category 3
Copper Powder 7440-50-8, EC#: 231-159-6	Acute Aquatic Toxicity Category 1 (M factor = 1) Chronic Aquatic Toxicity Category 2

Notes: CAS# = Chemical Abstracts Service Registration Number; EC# = European Community Number; GHS = Globally Harmonized System of Classification and Labelling of Chemicals (UN, 2019); M Factor = Multiplying Factor.