Any solid, liquid or gas substance that can be fatal or cause serious harm to your body when ingested is a poison. Of course, preventing poisoning is preferable to treating it - for example, keep poisonous cleansers out of reach of your baby sister or a child you're baby sitting. But accidents happen. Here's how you can help if you know someone who's been poisoned.
First, call a poison-control center (have the number of a local one near your phone). Many accidental poisoning can be treated at home, but get professional advice first.
If the victim can be treated at home, the object is to dilute the poison in the victim's stomach and then get him to vomit it up as soon as possible, but only if the poison is noncaustic (nonburning) - for example, aspirin, barbiturates, poisonous plants. Give the victim one or two glasses of water and then a tablespoon of syrup of ipecac, something every household should have. Follow with another glass of water. The ipecac should induce vomiting within 15 or 20 minutes; if it doesn't, repeat the dosage once. If you have no syrup of ipecac, place two fingers on the tongue back toward the tonsils to gag the victim and induce vomiting.
If the poison is caustic (acid), for example, ammonia, toilet bowl cleanser, bleach, lye, automatic dishwashing products, kerosene, gasoline or turpentine, do not induce vomiting. Corrosive substances do more harm coming back up than they do remaining in the stomach. Instead, unless you've been told otherwise by a doctor or poison-control center, dilute the poison in the victim's stomach with milk, milk of magnesia or an over-the-counter antidote that contains activated charcoal, which absorbs the chemicals in the poison and acts as a buffer in the stomach. Take the victim to the nearest doctor or poison control center.
If the poison has been inhaled in the form of oven gas or other toxic fumes, simply get the victim outside into fresh air immediately.