materials made of polyhydroxylated or polyaminated polymers can be rendered bacteriostatic or fungistatic by treating the materials with a solution of certain n - oxiranemethane n , n , n - trialkylammonium compounds in a base , and either spin drying the treated material and storing it protected from air for at least three hours , or drying the treated material and holding it at a temperature higher than 80 ° c .