The material of choice for an effective reduced-smoke burn barrel is steel. You should only use a burn barrel in accordance with local laws; many states specifically prohibit home burning of trash, while others have strict regulations concerning the materials that can be burned.
Reducing the amount of potentially toxic smoke produced by a burn barrel is important in order to protect the environment and comply with relevant legislation, even where local laws allow open fires and burn barrels. An open-head steel drum, drilled and modified to produce a clean burn, helps to achieve this. Using other materials may release pollutants in the air, in addition to the fumes from the burn.