Hazardous ChemicalsHazardous Materials & Dangerous Goods Posted on 9 February 20229 February 2022 by ORP DG PRO Hazardous substances are classified on the basis of their potential health effects, whether acute (immediate) or chronic (long-term). Dangerous goods are classified on the basis of immediate physical or chemical effects, such as fire, explosion, corrosion and poisoning. ORP DG PRO Lithium Battery Guidance Document Introduction to ORP