n-Butyl mercaptan

n-Butyl mercaptan (CAS 109-79-5) is an organosulfur compound also known as butanethiol, butylthiol, and MERCAPTAN C4, with FEMA designation 3478. It does not carry an E-code classification. The compound is commercially identified under these trade names across food flavoring and energy sector applications.

In food flavoring, n-butyl mercaptan contributes characteristic sulfurous, onion-like notes at trace concentrations, functioning as a flavor modifier in savory and meat profiles. In the oil and gas industry, it serves as an odorant or odorant precursor, providing a detectable warning scent in fuel gases due to its low odor threshold and chemical stability under pipeline conditions.

n-Butyl mercaptan is available as a liquid in FEMA-grade quality suitable for food applications and is subject to REACH registration requirements within the EU. Procurement should confirm compliance with applicable food safety frameworks and confirm packaging formats, typically small containers given the compound's volatility and handling requirements, with the supplying distributor.