Chemicals form an important part of the modern world. From powering our vehicles (petrol/diesel) to helping us increase the productivity of our farms (pesticides) and purifying our water (Chlorine), they play a vital role in our lives.

However, some of the properties of chemicals which make them valuable such as their ability to kill dangerous organisms in water and pests on crops, may sometimes pose a hazard to us and the environment. A hazardous chemical is any chemical that can do harm to your body and come in the form of explosives, flammable and toxic substances. These substances are most often released as a result of accidents in industries or because of transportation accidents.

Hazardous chemicals can be commonly categorized as:

Toxic Chemicals Chemicals like ammonia, chlorine and hydrogen sulphide, in high concentration, may cause immediate harm when it gets into the human body through different routes, especially when inhaled. It may affect the functioning of various vital organs leading to death or disability.
Flammable Chemicals Chemicals like petroleum products, LP Gas that we use for cooking etc. can catch fire very easily if it gets a source of ignition. Fires caused by large amounts of flammable chemicals can sometimes pose additional hazards and can sometimes even lead to an explosion.
Explosives Chemicals Some chemicals like ammonium nitrate can explode if not carefully handled and stored resulting in the damaging effects similar to bomb blasts that may happen during wartime.
Corrosive Chemicals Acids and bases are common corrosive chemicals. Such chemicals are capable of damaging skin, eyes and the respiratory system on contact.

Hazardous chemicals used in industries are generally stored or processed under controlled conditions. However any malfunction could result in a leak or an explosion involving such chemicals. Such events can release toxic chemicals into the atmosphere, or result in a fire or explosion that may cause loss of life and property even over a large area. Different types of industrial accidents that may happen in your town are :
 

Toxic release A toxic release is similar to the accident that happened in Bhopal where large number of people died and suffered injuries due to a leak of a toxic chemical called methyl isocyanate from an industry. It involves the leaking of a toxic chemical, which then spreads in the atmosphere and thereafter inhaled by people in the open, leading to injuries.

Fire An industrial fire can happen when a storage or process using such chemicals catches fire. The fire may cause the emission of heat radiation resulting in burns to people around the site of accident. If not controlled on time, such fires may result in an explosion or may result in the emission of toxic gases.

Explosions An explosion in a hazardous industry can be caused by the sudden detonation of an explosive chemical or also as a result of a fire engulfing a storage vessel resulting in pressure waves which may break glasses, damage buildings and throw shrapnel into the air.