1. Chlorofòrm is slowly oxidised by air in the presence of light to an extremely poisonous gas, carboxyl chloride (phosgene). it is therefore stored in closed dark coloured bottles completely filled so that air is kept out.
2. With the use of 1% ethanol we can stabilise chloroform, because ethanol can convert the poisonous COCl2 gas into non poisonous diethyl carbonate.
COCl2 + 2C2H5OH CO(OC2 H5)2 + 2HCl
