There are many chemicals that can cause loss of consciousness. Here are some common chemicals and drug categories that may cause loss of consciousness in a short period of time: 1. **Volatile chemicals**: Anesthetics such as ether, chloroform, and isoflurane act quickly on the central nervous system through inhalation, causing loss of consciousness. 2. **Sedatives and hypnotics**: Benzodiazepines (such as diazepam, lorazepam) and barbiturates (such as pentobarbital) can significantly depress central nervous system activity. 3. **Anesthetics**: Such as propofol, which is a general anesthetic that can quickly induce and maintain a state of unconsciousness through intravenous injection. 4. **Organic solvents**: Certain organic solvents (such as rapidly evaporating sprays) have the potential to cause loss of consciousness in a short period of time through inhalation, which is usually associated with abuse. These substances have legitimate uses in medicine and surgery, but if used improperly or with inadequate safety precautions, they may cause significant health risks or even endanger life. In any case, the use of these chemicals must follow professional advice and guidance. Abuse or misuse may result in serious health problems, so seek medical help immediately if you experience symptoms.