Incinerators are used to burn organic material, gases, fumes, hazardous waste, municipal trash, or sewage sludge at a high temperature, sometimes to produce energy. There are many different types of products. Examples include trash incinerators, waste incinerators, garbage incinerators, medical waste incinerators, crematory incinerators, and air curtain incinerators. The ash from a trash incinerator takes up less space than compacted waste. A waste incinerator or garbage incinerator can vary widely in terms of size and application. A small trash incinerator is designed for single-household use. By contrast, medium-sized trash incinerators are suitable for commercial, industrial or institutional applications. A large-scale garbage incinerator is designed to dispose of large volumes of municipal waste. A medical waste incinerator burns medical refuse at extremely high temperatures. A crematorium, or crematory incinerator, is a type of incinerator used to reduce corpses to bone fragments and ash. An air curtain incinerator is a combustion device (either stationary or portable) that forces high velocity air into a burn chamber with vertical walls to maintain a curtain of air over the surface of the burn chamber and re-circulate the air under the curtain.

Selecting incinerators requires an analysis of specifications such as materials of construction, power source, and physical dimensions. Traditionally, incinerators were used only to eliminate waste. Today, incinerators are also used to generate energy. Although incinerators represent an alternative to traditional energy sources as fossil fuels, their environmental impact is an important consideration. In addition to ashes, incinerators exhaust gases such as hydrogen chloride, sulphur dioxide and carbon dioxide. Consequently, many incinerator rebuild projects are being undertaken with the goal of implementing emission controls and monitoring systems. In the United States, the Environmental Protection Agency (EPA) and corresponding state agencies regulate the use of incinerators and incineration practices. Local authorities regulate the disposal of incinerated wastes.