A colorless volatile alkaline liquid, N.(CH3)3, obtained from herring brine, beet roots, etc., with a characteristic herringlike odor. It is regarded as a substituted ammonia containing three methyl groups.

Trimethylamine, also known as NMe3, N(CH3)3, and TMA, is a colorless, hygroscopic, and flammable simple amine with a typical fishy odor in low concentrations and an ammonia-like odor in higher concentrations. Trimethylamine has a boiling point of 2.9 °C and is a gas at room temperature. Trimethylamine usually comes in pressurized gas cylinders or as a 40% solution in water.