Vehicles and freight containers are to be marked with warning symbols if they contain any quantity of Class A or B explosives, poison gas, flammable solids, or radioactive or corrosive materials. Vehicles and freight containers must carry warning placards if they contain 1,000 pounds or more of blasting agents, flammable or non-flammable gas, chlorine, oxygen, flammable or combustible materials, flammable liquids or solids, oxidizers, organic peroxides, poisons, corrosive or irritating materials or Class C explosives (Class C explosives and irritating materials are marked "dangerous").
How to report a spill:
If you come across a toxic spill or are exposed to a toxic substance, and the substance either appears to be dangerous or could lead to an emergency situation, don't get near it, and immediately call 911. If you know what the substance is, identify it at the time you place the call. Substances with a strong, acid odor that burn the eyes, nostrils and lungs--such as nitric acid and any ammonia combination--should be considered an emergency situation. Non-emergency situations--for instance, if you come across someone discarding waste oil or find any abandoned, structurally intact drums--should be reported to the county's Health Care Agency, Environmental Health Division, at (714) 834-8175 during regular business hours (Monday through Friday from 8 a.m. to 5 p.m.); during off-hours call 911.