There are a number of chemicals used in workplaces. Most staff will have at least some contact with cleaning aids. It is unlikely that these will be classified as hazardous substances. However, to some workers who are more sensitive to chemicals, even common solutions can cause illness, skin irritation, or breathing problems.
Liquids like cleaning products, paints, acids, solvents – ESPECIALLY if chemicals are in an unlabelled container!
Vapors and fumes that come from welding or exposure to solvents
Gases like acetylene, propane, carbon monoxide and helium (yes it's not healthy to suck on a helium balloon and sound like a chimpmunk)
Flammable materials like gasoline, solvents, and explosive chemicals
Pesticides
Most products will have information on safe use, personal protective equipment (eg gloves, eye protection) and first aid treatment on the container or packaging. Read the container before using any substance.