Disinfection of sputum is done by?

Boiling: Vegetative bacteria killed almost immediately at 90-100 degree Celsius but sporing bacteria requires prolonged periods of boiling. Boiling is not recommended for sterilizing of instruments used for surgical procedure and should be regarded only as a means of disinfectant. Nothing sho of autoclaving at high pressure can destroy spore and ensure sterilization. Hard water should not be used. Sterilization may be promoted by the addition of 2% sodium bicarbonate to water. in the case where boiling is considered adequate, The material should be immersed in the water and boiled for 10-30 minutes. The lid of sterilizer should not be opened during the period ref:Ananthanarayan and Panicker's Textbook ofMicrobiology 8thEdition pg no:32-33