Even in the smallest laboratory, dangerous chemicals are used directly or incorporated into stains and reagents. Hence the correct handling and storage of hazardous chemicals is essential to prevent injury and damage. In addition to this, to reduce accidents caused by chemicals, labeling is very important.
These include ether, xylene, toluene, methanol, ethanol, other alcohol, glacial acetic acid, acetone, and acetic anhydride. Alcoholic Romanov sky stains and acid alcohol solutions are also highly flammable.
Storage: Flammable chemicals should be stored in a fire proof metal box at ground level, preferably in and outside cool and locked store. If a metal box is not available, at least a container well lined with tin foil should be used.
Corrosive chemicals include strong acids such as concentrated sulfuric acid, nitric acid, glacial acetic acid, trichloroacetic acid, ortho – phosphoric acid, and caustic alkalis such as sodium hydroxide (caustic soda) and potassium hydroxide (caustic potash).
Storage: Corrosive chemicals should be stored at low level to avoid any serious injury, which could be caused if they are accidentally knocked off a shelf.
Toxic, harmful, and irritating chemicals
Toxic chemicals are those chemicals which can cause death or serious ill-health if swallowed or inhaled, or if the chemical is allowed to come into contact with the skin. Examples of toxic chemicals include potassium cyanide, sodium nitroprusside, formaldehyde solution, chloroform, barium chloride and methanol.
Harmful chemicals can cause ill- heath if swallowed and inhaled, or by skin contact. Example, iodine and sulphanilic acid chemicals can cause inflammation and irritation of the skin, mucous membranes, and respiratory tract.
Storage: Highly toxic chemicals such as potassium cyanide must be kept in a locked cupboard. Stock solutions or solids of harmful and irritating chemicals should be stored safely in cap board, not on an open shelf.
These chemicals include chlorates, perchlorates, strong peroxides, potassium dichromate, and chromic acid.
Storage: Oxidizing chemicals must be stored away from organic materials and reducing agents. They can produce much heat when in contact with other chemical, especially flammable chemicals.
Heat, flame, or friction can cause explosive chemicals to explode. An example of explosive chemical is picric acid, which must be stored under water. If picric acid is allowed to dry, it can become explosive. This can occur if the chemical is left to dry in pipes without being flushed away with adequate amount of water.
A chemical that can cause cancer by ingestion, inhalation, or by skin contact is known as a carcinogen. Chemicals with proven carcinogenic properties include benzene, 0rtho – tolidine, alpha and beta- naphthylamine, nitrosamines and selenite. The risk in handling of these chemicals is proportional to the length and frequency of the exposure and the concentration of the chemical.
Storage: Carcinogens should be kept in closed containers and labeled as ‘carcinogenic, handle with special precautions’.