Ten commercially available disinfectants were tested at high pH in 2% sodium hydroxide and low pH in 2% acetic acid as inactivants for African swine fever (ASF) in a protein-rich blood-spleen homogenate. As assayed in leukocyte cultures, sodium hydroxide and acetic acid, sodium meta silicate and Roccal did not inactivate ASF virus in 1 hr at 22 to 25 C. Some viricidal activity as assayed in leukocyte cultures was found with Weladol, Triton X-100 Amphyl, pHisoHex, sodium dodecyl sulfate, LpH, Environ, Environ D, and One-Stroke Environ. Of these, the last four appeared to be most promising. When assayed in pigs, only One-Stroke Environ (1/E) was viricidal. Concentrations of 1.0, 0.75, and 0.5 were effective, but, at 0.25%, virus was not inactivated. The minimal time to inactivate ASF virus by 1% 1/E is 60 min. A room contaminated with ASF virus was made safe for pigs after 1 hr by spraying with 1% 1/E. The most active component of 1/E is o-phenylphenol. Although another component of 1/E, i.e., o-benzyl-p-chlorophenol, also has some activity, the mixture of the active components of 1/E is most effective against ASF virus. One of the soluble antigens associated with ASF virus is destroyed by 1/E.