( iii ) Tincture of iodine is a 2-3 % solution of iodine in alcohol , which is a powerful antiseptic for wounds .
( iv ) Iodoform ( CHI3 ) is also used as an antiseptic for wounds . ( v ) Boric acid in dilute aqueous solution is weak anIUS4 ! pa eyes .
3 . Disinfectants
These are the chemical substances which kill microorganisms not safe to be applied to the living tissues . They are generally kill the microorganisms present on inanimate objects such as drainage systems , instruments , etc .
Some common examples of disinfectants are as follows :
( i ) 1 % phenol solution is disinfectant while in lower concentration 0.2 % solution of phenol is antiseptic .
( ii ) 0.2-0.4 ppm aqueous solution of chlorine is used for sterilisation of water to make it fit for drinking purpose .
( iii ) SO2 at very low concentrations behaves like disinfectant .
( iv ) Formaldehyde ( HCHO ) in the disinfecting rooms and operation gaseous theatres forms is used in hospitals . for
Antifertility Drugs
These are the chemical substances used to control the pregnancy . These are also called oral contraceptives . They belong to the class of natural products , known as steroids .
Birth control pills essentially contain a mixture of synthetic estrogen and progesterone derivatives . Norethindrone is widely used as antifertility drug .
Chemicals in Food
1 . Artificial Sweetening Agents
Sucrose ( table sugar ) and fructose are the most widely used natural sweeteners . But they add to our calorie intake and promote tooth decay . To avoid these problems many people take artificial sweeteners .