CarCareTruth

Phosphoric Acid

  • Acids
  • CAS 7664-38-2
  • IUPAC: phosphoric acid

Corrosive at concentrations above 10% (H314 — skin burns and eye damage). In consumer-diluted wheel cleaner formulas (typically 2–8%), corrosivity is reduced. Signal word DANGER at concentrate; WARNING at diluted consumer-use concentrations.

Phosphoric acid is the active acidic agent in most rust converters and many wheel cleaners. At concentrations above 10%, it is corrosive and requires appropriate PPE (H314). In consumer-diluted wheel cleaner formulas (typically 2–8%), corrosivity is reduced but H302 and H290 still apply at concentrate handling stage. ## Regulatory status - Not listed under California Prop 65 - Not restricted under EU REACH - Widely used in food-grade applications (E338) at high purity grades

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: Rust converter, pH adjuster, and surface prep agent in wheel cleaners and rust converters

No products on file contain this (yet)

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