Replacement of fumigation with formalin

now a days formalin getting ban, kindly share your views about it replacement.
if there is a good replacement please name it.and its dilutions and time of exposure. in sterile area for class A.

Yes, you are right formaldehyde is not used for fumigation. Hydrogen peroxide solution or a solution of hydrogen peroxide and silver nitrate are used for fogging in classified areas.

sir, what quantity should be used of both? Hydrogen Peroxide and Silver Nitrate