The partial oxidation of hydrocarbons and decomposition of complex organic substances produce formal aldehyde which is a powerful antiseptic. It is also interesting to note that germicidal action of formaldehyde is only effective in the presence of water vapor which is also produced in large quantities in Yagya. The use of formaldehyde spray for disinfecting of walls, ceiling etc., is common and such a spray is automatically produced when Yagya is performed.
The oxidation of hydrocarbons also produces formic acid and acetic acid both of which are good disinfectants. Use of formic acid for preservation of fruits and that of acetic acid in preserving vinegar is a common practice.
The antiseptic and antibiotic effects of fumes of Yagya have also been examined by conducting suitable experiments on rabbits and mice and it has been established that fumes emitted in Yagya are powerful antibiotic. Agnihotra ash purifies and cleanses the water making it fit for drinking.