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CarCareTruth

Morpholine

  • Corrosion inhibitors
  • CAS 110-91-8
  • IUPAC: Tetrahydro-1,4-oxazine

Morpholine (CAS 110-91-8) appears in 7 of the 2,122 car-care products CarCareTruth tracks (as of August 2026). It is classified as a VOC.

Neat morpholine is corrosive (H314 skin corrosion Cat 1B, causes severe eye damage) and harmful by oral, dermal, and inhalation routes (H302+H312+H332). In consumer aerosol cleaning products at <5% concentration, dilution below the H314 classification threshold means the mixture carries H319 (eye irritation) rather than H318 (serious eye damage). Listed on EU CMR, IARC Group 3 (not classifiable as carcinogenic), and multiple priority chemical watchlists.

Morpholine (tetrahydro-1,4-oxazine) is a six-membered heterocyclic amine containing both nitrogen and oxygen in the ring. It functions as a solvent and corrosion inhibitor in cleaning products, waxes, and metal-working fluids. Its alkaline character (pH ~8.5 in dilute solution) makes it effective as a co-solvent that boosts surfactant penetration into fabric and carpet fibers.

At neat concentration, morpholine carries serious health hazards: skin corrosion (Cat 1B), harmful if swallowed/inhaled/in contact with skin, and flammable liquid (Cat 3). In consumer aerosol formulations where it appears at <5% concentration, the mixture classification drops to eye irritation (H319) and the flammable aerosol classification comes from the hydrocarbon propellant rather than morpholine itself. California Right to Know Act disclosures list morpholine as a disclosed ingredient in several aerosol carpet and upholstery cleaners.

Health & environment profile

VOC
yes
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
yes
Biodegradable
yes
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
2/5
Purpose: Solvent and corrosion inhibitor in aerosol cleaning formulations — acts as a co-solvent and pH buffer that helps surfactants penetrate soiled fibers

Common questions about Morpholine

What is Morpholine used for in car care?
Solvent and corrosion inhibitor in aerosol cleaning formulations — acts as a co-solvent and pH buffer that helps surfactants penetrate soiled fibers
Is Morpholine a VOC?
Yes. Morpholine is classified as a volatile organic compound (VOC).
Is Morpholine on California's Proposition 65 list?
No. Morpholine is not on California's Proposition 65 list.
Is Morpholine biodegradable?
Yes. Morpholine has a confirmed biodegradable profile.

7 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.