Asphyxiants are substances that cause suffocation by depriving a person of oxygen. Synonyms for asphyxiant include suffocant, smothering agent, choking gas, and toxic air. Nitrogen, argon, and helium, which are commonly used in industrial processes, can also act as asphyxiants if they displace oxygen from the air. Other gases that are known to cause asphyxiation are carbon dioxide, methane, and hydrogen sulfide. It is important to be aware of these potential hazards when working in confined spaces or using chemicals that can release toxic gases. Employers should ensure that proper safety measures are in place to prevent asphyxiation in the workplace.