Zinc Dialkyldithiophosphate (ZDDP)
- Other
- CAS 68457-79-4
- IUPAC: zinc bis(O,O-dialkyl dithiophosphate)
Harmful if swallowed (H302). May cause an allergic skin reaction (H317). Toxic to aquatic life with long-lasting effects (H411). Signal word WARNING. Heavy metal content (zinc) and endocrine disruption in aquatic organisms at elevated concentrations.
ZDDP (zinc dialkyldithiophosphate) is the primary anti-wear additive in conventional and many synthetic motor oils. It forms a protective tribofilm on metal surfaces, preventing wear on camshafts and lifters — particularly important for flat-tappet engines.
ZDDP levels have been reduced in modern API SN/SP oils due to catalytic converter compatibility concerns (phosphorus poisons the catalyst). Older engines with flat-tappet cams often require supplemental ZDDP additives.
`endocrine_disruptor: true` — zinc ions have documented endocrine disruption effects in aquatic organisms. `heavy_metal_containing: true` — zinc.
## Regulatory status
- Not Prop 65 listed in the US
- EU classified as environmentally hazardous (H411)
Health & environment profile
- VOC
- no
- Prop 65 listed
- no
- Asthmagen
- no
- EPA Safer Choice
- no
- Aquatic toxicity
- yes
- Biodegradable
- no
- Bioaccumulative
- no
- Persistent
- yes
- Ozone depleting
- no
- Microplastic
- no
- PFAS
- no
- Env. score
- 2/5
No products on file contain this (yet)
Health summaries are editorial — we synthesize from SDSs, peer-reviewed sources, and regulatory listings. Not medical advice.