Heat labile instruments for use in surgical procedure can be best sterlized by :
“Heat sensitive articles may be sterilized at 55-60 0 C by ethylene oxide which kills bacteria, spores, viruses.”

It is highly penetrating and highly explosive.
CO2 or N2 decrease its explosive tendency and water vapour increase its efficacy.
It acts as alkylating agent.
It is specially used for sterlizing heart - lung machines, sutures, dental equipment, books, fabrics, plastic equipment, cardiac catheters, clothing, glass, plastics, metal and paper surfaces.
It is unsuitable for fumigating room since it is explosive.
Absolute alcohol
Ultra violet rays
Chlorine releasing compounds
Ethylene oxide gas