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CarCareTruthProducts · Ranked

Urea

  • Reducers
  • CAS 57-13-6
  • IUPAC: diaminomethanone

Urea (CAS 57-13-6) appears in 7 of the 1,812 car-care products CarCareTruth tracks (as of June 2026). It is readily biodegradable.

Not classified as hazardous under GHS/WHMIS at 32.5% concentration. Very high LD50 values (oral rat 8,471 mg/kg). Minor transient eye discomfort possible on direct splash contact.

Urea (carbamide, CAS 57-13-6) is a naturally occurring organic compound and the primary functional ingredient in diesel exhaust fluid (DEF). At 32.5% concentration in deionized water (per ISO 22241), urea is injected into diesel exhaust streams where it decomposes to ammonia, which then reacts with NOx over an SCR catalyst to form nitrogen and water.

Urea has an extremely low acute toxicity profile — oral LD50 in rats is approximately 8,471 mg/kg. It is not classified as a skin or eye irritant under GHS at the concentrations present in commercial DEF, though prolonged high-concentration exposure to eyes can cause mild transient irritation. It is not a carcinogen, reproductive toxin, asthmagen, or sensitizer.

Environmentally, urea is rapidly biodegradable and does not bioaccumulate. At agricultural application rates, urea contributes to soil and water eutrophication through nitrogen loading, but consumer-quantity DEF use does not approach environmentally significant runoff levels. No GHS aquatic toxicity classifications apply at DEF-product concentrations.

Health & environment profile

VOC
no
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
4/5
Purpose: Active component in diesel exhaust fluid (DEF); reduces NOx emissions via selective catalytic reduction (SCR)

Common questions about Urea

What is Urea used for in car care?
Active component in diesel exhaust fluid (DEF); reduces NOx emissions via selective catalytic reduction (SCR)
Is Urea a VOC?
No. Urea is not classified as a volatile organic compound (VOC).
Is Urea on California's Proposition 65 list?
No. Urea is not on California's Proposition 65 list.
Is Urea biodegradable?
Yes. Urea 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.