CarCareTruth

Linear Alkylbenzene Sulfonate (LAS)

  • Anionic surfactants
  • CAS 68081-81-2

Causes skin irritation and serious eye damage at working concentrations. At car-wash dilution ratios (1-3 oz per 5 gal), exposure is minimal. Readily biodegradable but acutely toxic to aquatic organisms — don't dump wash water into storm drains.

Linear alkylbenzene sulfonates (LABS/LAS) are the workhorse anionic surfactants in most car wash shampoos. They produce the thick foam that lubricates the wash mitt and lifts dirt away from paint. At concentrate strength they're a skin and eye irritant (GHS signal word: Danger, H315/H318), but at the 1-3 oz per 5-gallon dilution used in a wash bucket the irritation risk is negligible. The bigger concern is aquatic toxicity — EC50 for fish is around 0.86 mg/L, so undiluted wash runoff entering waterways is harmful. LAS are readily biodegradable (93%+ mineralization within 28 days), so the environmental persistence is low.

Health & environment profile

VOC
no
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
3/5
Purpose: Primary anionic surfactant — generates foam and lifts grease/dirt from surfaces

1 product contain this

Health summaries are editorial — we synthesize from SDSs, peer-reviewed sources, and regulatory listings. Not medical advice.