Acutely toxic chemicals may cause harm if it enters the body. They may enter the body in different ways called the ‘route of exposure’. The most common is through inhalation (breathing it into the lungs). Another common route of entry is through skin contact. Some materials can easily pass through unprotected skin and enter the body. Ingestion is another, less common, route of exposure. Ingestion often occurs accidentally through poor hygiene practices (e.g. eating food or smoking a cigarette using contaminated hands).
There are different degrees of toxicity with some chemicals being fatal, toxic or harmful, if swallowed, in contact with skin, or inhaled. While restricted, it is still possible to find acutely toxic chemicals in consumer products, so it is very important that you always read the labels and safe use instructions before using any products.