Hazardous substances include chemicals (that people make or work with directly), dust, fumes and bacteria.
Exposure can happen by breathing them in, contact with the skin, splashing them into the eyes or swallowing them. If exposure isn't prevented or properly controlled, it can cause serious illness (including cancer, asthma and dermatitis) and sometimes even death.
What should I do?
If you are concerned that there has been contact with a hazardous substance, or a spillage or chemical accident has occurred, call 999 giving as much information as you can about the nature of the substance.
If you believe that you are suffering from the affects of exposure to a hazardous substance, you should make an appointment with your doctor.