Is 2,5-Bis(octyldithio)-1,3,4-thiadiazole a VOC?

No. 2,5-Bis(octyldithio)-1,3,4-thiadiazole is not classified as a volatile organic compound (VOC).

Is 2,5-Bis(octyldithio)-1,3,4-thiadiazole on California's Proposition 65 list?

No. 2,5-Bis(octyldithio)-1,3,4-thiadiazole is not on California's Proposition 65 list.

CarCareTruth.com Products · Ranked

2,5-Bis(octyldithio)-1,3,4-thiadiazole

Q: What is 2,5-Bis(octyldithio)-1,3,4-thiadiazole used for in car care?

Multifunctional extreme-pressure, antiwear, and copper corrosion inhibitor used in synthetic lubricants. Protects ferrous and non-ferrous metal surfaces under load.

Corrosion inhibitors
CAS 13539-13-4
IUPAC: 2,5-bis(octyldithio)-1,3,4-thiadiazole

2,5-Bis(octyldithio)-1,3,4-thiadiazole (CAS 13539-13-4) appears in 1 of the 1,812 car-care products CarCareTruth tracks (as of June 2026).

No health H-codes at typical use concentrations (<1% in formulated products). Skin and eye irritation data not established at product-use levels. No Prop 65 listing.

2,5-Bis(octyldithio)-1,3,4-thiadiazole is a sulfur-containing heterocyclic compound used as an antiwear and corrosion inhibitor additive in synthetic lubricants, particularly for protecting copper alloys and ferrous metals from oxidation and wear under load. It belongs to the thiadiazole family of metal deactivators and extreme-pressure additives.

At the trace concentrations used in finished lubricant formulations (typically <1%), this compound does not carry GHS health hazard classifications. It is a persistent organic compound and is not readily biodegradable.

Health & environment profile

VOC: no
Prop 65 listed: no
Asthmagen: no
EPA Safer Choice: no
Aquatic toxicity: no
Biodegradable: no
Bioaccumulative: no
Persistent: no
Ozone depleting: no
Microplastic: no
PFAS: no
Env. score: 3/5

Purpose: Multifunctional extreme-pressure, antiwear, and copper corrosion inhibitor used in synthetic lubricants. Protects ferrous and non-ferrous metal surfaces under load.

Common questions about 2,5-Bis(octyldithio)-1,3,4-thiadiazole

What is 2,5-Bis(octyldithio)-1,3,4-thiadiazole used for in car care?: Multifunctional extreme-pressure, antiwear, and copper corrosion inhibitor used in synthetic lubricants. Protects ferrous and non-ferrous metal surfaces under load.
Is 2,5-Bis(octyldithio)-1,3,4-thiadiazole a VOC?: No. 2,5-Bis(octyldithio)-1,3,4-thiadiazole is not classified as a volatile organic compound (VOC).
Is 2,5-Bis(octyldithio)-1,3,4-thiadiazole on California's Proposition 65 list?: No. 2,5-Bis(octyldithio)-1,3,4-thiadiazole is not on California's Proposition 65 list.

1 product contain this

Royal Purple Maxfilm Synthetic Penetrating Lubricant
penetrating-oil
Prop 65

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.