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Prices may varyHealth score is for adult use as intended, per the manufacturer's SDS. It does not model child ingestion, accidental spill cleanup, or off-label use. See the safety panel below for full hazard classification, and /disclaimer for the full editorial scope.
GHS hazard codes are quoted from the manufacturer’s Safety Data Sheet. PPE tiers below translate those codes and the listed ingredient chemistry; they are not CarCareTruth recommendations.
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From the manufacturer’s Safety Data Sheet, Section 8
“SDS §2 (Rev 004.1) carries no H319 classification. Back-of-bottle 'May cause eye irritation' is pre-2025 label copy not reflected in current GHS classification. Situational tier from splash_risk · incidental eye contact during handling is the only residual pathway given boilerplate-only language.”
— Loctite
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
No PPE specified in published sources for skin. Absence does not imply “not needed” — consult the full Safety Data Sheet.
From the manufacturer’s Safety Data Sheet, Section 8
“No inhalation H-codes classified in SDS §2. Silicone paste is non-volatile at application temperatures. Situational tier for enclosed spaces per health.md · not_needed is schema-invalid for chemical products.”
— Loctite
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
No PPE specified in published sources for ventilation. Absence does not imply “not needed” — consult the full Safety Data Sheet.
PPE tiers translate the manufacturer’s SDS and U.S. regulatory standards. Not professional safety advice. How we report safety.
This product ranks #1 of 8 in Dielectric Grease.
Last reviewed June 9, 2026
TL;DR Solid protection for spark plug boots, trailer connectors, and battery terminals; it's highly rated on Amazon and broadly trusted by owners, though no multi-season community teardown data is available to confirm long-term hold.
This Loctite tube lays a moisture-proof silicone barrier on spark plug boots, trailer hitch connectors, and battery terminals, blocking salt, dirt, and water to stop pin oxidation and voltage leakage. A thin coat inside a boot or on connector pins takes under a minute. The standard 80ml tube works well for routine home service; apply sparingly to avoid flooding multi-pin connectors.
Best for anyone doing a spark plug service, maintaining trailer or tow-vehicle connectors, or protecting battery terminals in a wet climate. The tube format is cost-effective for multi-vehicle households. Skip it if you only need one connector's worth; a single-use packet from a generic brand costs less.
The 2025 SDS carries no GHS hazard classifications; the signal word is absent. A California Prop 65 listing appears in SDS §15, related to a substance in the formulation. Lungs: situational (enclosed space). Eyes: situational (splash risk).
CarCareTruth scores Loctite 37535 Dielectric Tune-Up Grease at 7.2 out of 10 on the composite CCT score, with a health sub-score of 8.8/10. The CCT score blends real-world effectiveness, ingredient health impact pulled from the manufacturer's safety sheet, and environmental footprint against a published category rubric. See the methodology link on this page for the full scoring breakdown.
Per the Safety Data Sheet ingredient disclosure: Silica, amorphous, fumed, crystal-free (CAS 112945-52-5): 5·10% · thickening agent. Silicone Resin (PDMS base, proprietary, no CAS): balance. Source: SDS Rev 004.1, 2025-11-12, Henkel API (IDH 495549).
Marketing copy from Loctite, via Amazon. Not editorial.
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