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CarCareTruth

Dipropylene Glycol n-Butyl Ether (DPnB)

  • Glycol ether solvents
  • CAS 29911-28-2
  • IUPAC: 1-(2-butoxypropoxy)propan-2-ol

Dipropylene Glycol n-Butyl Ether (DPnB) (CAS 29911-28-2) appears in 3 of the 2,122 car-care products CarCareTruth tracks (as of August 2026). It is classified as a VOC.

At concentrate strength this propylene glycol ether is classified H315 (causes skin irritation); below about 2% in finished products it falls under the classification threshold. It is not on California's Prop 65 list and is not classified as a respiratory sensitizer, asthmagen, carcinogen, or reproductive toxicant. Propylene glycol ethers are generally lower-toxicity than the ethylene glycol ether family.

Dipropylene glycol n-butyl ether (DPnB) is a high-boiling-point glycol ether (boiling point ~229°C) widely used as a co-solvent in water-based cleaners and disinfectants. It is a member of the propylene-glycol-ether family (P-series) — generally considered lower-toxicity than the ethylene-glycol-ether family (E-series) which includes 2-butoxyethanol.

Health classifications:

  • H315 (skin irritation) at concentrate strength; below threshold at <2% in finished products
  • Not classified as a respiratory sensitizer or asthmagen
  • Not on Prop 65 list — propylene glycol ethers are NOT in the same Prop 65 category as ethylene glycol ethers
  • Acute oral toxicity: low (rat LD50 >5,000 mg/kg)

Environmental:

  • Readily biodegradable per OECD 301
  • Low aquatic toxicity (LC50 >100 mg/L for fish)
  • VOC: yes (low vapor pressure but classified VOC). At 1-2% in finished products, contributes <20 g/L absolute VOC.
  • Not bioaccumulative; not persistent; not PFAS

In OdoBan and similar quat-based disinfectants, DPnB is the coupling-agent / co-solvent that helps the antimicrobial active wet hard surfaces and penetrate organic soils. Use concentration is typically 1-2% in RTU and 5-10% in concentrates.

Health & environment profile

VOC
yes
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
yes
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
5/5
Purpose: Glycol ether co-solvent — used in water-based cleaners and disinfectants as a coupling agent and surfactant aid; helps dissolve oily soils and improves cleaner penetration into porous substrates

Common questions about Dipropylene Glycol n-Butyl Ether (DPnB)

What is Dipropylene Glycol n-Butyl Ether (DPnB) used for in car care?
Glycol ether co-solvent — used in water-based cleaners and disinfectants as a coupling agent and surfactant aid; helps dissolve oily soils and improves cleaner penetration into porous substrates
Is Dipropylene Glycol n-Butyl Ether (DPnB) a VOC?
Yes. Dipropylene Glycol n-Butyl Ether (DPnB) is classified as a volatile organic compound (VOC).
Is Dipropylene Glycol n-Butyl Ether (DPnB) on California's Proposition 65 list?
No. Dipropylene Glycol n-Butyl Ether (DPnB) is not on California's Proposition 65 list.
Is Dipropylene Glycol n-Butyl Ether (DPnB) biodegradable?
Yes. Dipropylene Glycol n-Butyl Ether (DPnB) has a confirmed biodegradable profile.

3 products contain this

Related

Health and environment notes translate the manufacturer Safety Data Sheet, the GHS classification, and authoritative regulatory listings (California Prop 65, EPA). Not medical advice. They describe the ingredient itself; whether a hazard applies to a finished product depends on its concentration and how it's used.