Diethylene Glycol Monobutyl Ether

Diethylene glycol monobutyl ether (DGBE, butyl carbitol, CAS 112-34-5) is a glycol ether co-solvent used in alkaline cleaners, degreasers, and industrial maintenance products. It is the diethylene glycol analog of 2-butoxyethanol (butyl Cellosolve) — same butyl head group, but with an extra ethyleneoxy unit that makes it less volatile and somewhat less skin-penetrating than its monoethylene cousin. **Health profile at ingredient level:** H319 (eye irritation Cat 2) is the primary classification. No H314 or H318 (not corrosive/serious eye damage at ingredient level). No H315 (not classified as a skin irritant at ingredient level). ACGIH TLV 10 ppm TWA; OEHHA REL 60 mg/m³. At typical APC working-solution concentrations (0.1–0.5%), the contribution to eye/skin irritation is low. **Environmental profile:** Readily biodegrades aerobically. Aquatic toxicity is low at mg/L concentrations typical of diluted cleaning effluent. VOC under CARB/EPA regulations at ~740 g/L pure; at APC working-solution concentrations (0.1–0.5%), VOC contribution is ~0.7–3.7 g/L — below all regulatory brackets.