Propane is primarily used for petrochemical production, but also for farming, transportation, heating, and cooking. Propane is a colorless and odorless gas at room temperature. Propane remains a liquid until it boils into a gas much closer to room temperature and pressure than methane. Almost 47 % of propane in the United States is used for petrochemical products such as plastics. Propane can be cracked in a steam cracker to produce propylene and ethylene, which are used to make plastics. The second largest percentage of propane in the US is used for home and commercial heating and cooking, where it is better known as liquified petroleum gas (LPG). The small remaining percentage of propane in the US is used for farm use, crop drying in particular.