This is a question posed by one of our readers…
Most codes and standards—at least regarding allowable concentrations of various substances—are promulgated by domestic jurisdictions, whether at the state/province or national governmental level.
However, there are numerous international organizations that publish recommendations on best practices and safe handling of chemicals, including:
Center for Chemical Process Safety
International Occupational Hygiene Association
International Program on Chemical Safety (IPCS)
National Fire Protection Association (NFPA)–which despite the name is truly international
World Health Organization International Programme on Chemical Safety