disinfectant

Disinfectant refers to a chemical agent used to inactivate or destroy pathogenic microorganisms on inanimate surfaces. They differ from antiseptics, applied to living tissue, and from sanitizers, which reduce microbial counts to safe levels on surfaces or equipment. Disinfection aims for a defined reduction in viable organisms on nonliving objects such as floors, countertops, instruments, and water or food processing equipment.

Most disinfectants act by chemical interference with cellular components. Oxidizing agents like chlorine and hydrogen peroxide destroy proteins, lipids, and nucleic acids. Alcohols disrupt membranes and proteins; quaternary ammonium compounds alter membranes and metabolism. Spectrum, concentration, and contact time vary by agent.

Disinfectants are categorized by activity and use context. In healthcare and industry, high-level and intermediate-level disinfectants are used on equipment contacting mucous membranes or nonintact skin; lower-level products disinfect noncritical surfaces. Household products provide surface disinfection for everyday use.

Effective disinfection depends on proper use: pre-cleaning to remove soil, correct concentration, adequate contact time, and appropriate temperature, with minimal organic load. Some agents can corrode or discolor materials and pose hazards to humans or the environment; follow manufacturer instructions and safety data sheets.

Regulatory guidance varies by country. In the United States, many disinfectants are registered with the Environmental Protection Agency and labeled with usage instructions, contact times, and safety precautions. In water treatment, chlorine or chloramine disinfects drinking and recreational water under public health standards.