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Distillates, Petroleum, Hydrotreated Heavy Naphthenic

  • Aliphatic solvents
  • CAS 64742-52-5

Distillates, Petroleum, Hydrotreated Heavy Naphthenic (CAS 64742-52-5) appears in 20 of the 2,122 car-care products CarCareTruth tracks (as of August 2026).

Aspiration hazard if swallowed (H304) — do not induce vomiting. Low acute oral and dermal toxicity (LD50 >5000 mg/kg). Not classified as a skin irritant or eye irritant. Mildly naphthenic hydrocarbon fraction; hydrotreating removes most PAH concern.

Hydrotreated heavy naphthenic petroleum distillates are a refined lubricant base stock fraction used to provide viscosity modification and residual lubricity in penetrating oils, metalworking fluids, and industrial lubricants. The hydrotreating process saturates aromatic rings and removes sulfur compounds, reducing the PAH content compared to unrefined naphthenic stocks.

In penetrating oils this fraction contributes to the residual lubricant film that reduces re-seizure risk after the initial penetration event. It has lower volatility than the light aliphatic fractions, so it tends to remain on the fastener longer. Ecotoxicity data is favorable compared to aromatic fractions — aquatic LC50 >5000 mg/L fish indicates low direct aquatic toxicity — but like all petroleum fractions it is not readily biodegradable.

The H304 (aspiration hazard) classification is standard for petroleum fractions and reflects the risk of aspiration pneumonitis if swallowed, not a vapor inhalation hazard during normal use.

Health & environment profile

VOC
no
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
no
Bioaccumulative
no
Persistent
yes
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
2/5
Purpose: Carrier solvent and viscosity modifier in lubricants and penetrating oils

Common questions about Distillates, Petroleum, Hydrotreated Heavy Naphthenic

What is Distillates, Petroleum, Hydrotreated Heavy Naphthenic used for in car care?
Carrier solvent and viscosity modifier in lubricants and penetrating oils
Is Distillates, Petroleum, Hydrotreated Heavy Naphthenic a VOC?
No. Distillates, Petroleum, Hydrotreated Heavy Naphthenic is not classified as a volatile organic compound (VOC).
Is Distillates, Petroleum, Hydrotreated Heavy Naphthenic on California's Proposition 65 list?
No. Distillates, Petroleum, Hydrotreated Heavy Naphthenic is not on California's Proposition 65 list.

20 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.