CarCareTruth Score
Decent.
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Prices may varyAbout this product's hazards. This product's Safety Data Sheet uses signal word danger. Read the manufacturer's SDS and follow all safety instructions before use. CarCareTruth ratings translate the manufacturer's safety sheet. They do not replace the SDS or substitute for a hazard assessment specific to your task.
Health 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 classifies the product as H319 (Cat 2 serious eye irritation) · not H318. Aerosol spray with acetone vapor pressure 231 mmHg generates inhalable mist that can drift toward the face during application; SDS §8 directs 'Avoid eye contact. Always spray away from your face.'”
— WD-40
U.S. regulatory standard
29 CFR 1910.133(a)(1)
“The employer shall ensure that each affected employee uses appropriate eye or face protection when exposed to eye or face hazards from… liquid chemicals…”
ANSI Z87.1 (incorporated via §1910.6)
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
From the manufacturer’s Safety Data Sheet, Section 8
“SDS §2 mixture classification does not include H315. Heptane carries H315 at the §3 ingredient level only. SDS §8 directs 'Avoid prolonged skin contact. Chemical resistant gloves recommended for operations where skin contact is likely' · situational rather than required for typical brief spray application.”
— WD-40
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
From the manufacturer’s Safety Data Sheet, Section 8
“SDS §2 lists H336 (may cause drowsiness or dizziness · CNS narcosis from acetone/heptane/IPA vapor) alongside the DANGER signal word and H222 extreme aerosol flammability. H336 is a health-tier H-code, so the DANGER classification is co-driven by a real biological hazard · not flammability alone. H335 (respiratory irritation per se) is not present, and no H331/H330/H334 codes that would force the 'required' tier. The 231 mmHg vapor pressure and aerosol form factor warrant chemistry-genuine respiratory PPE; SDS §8 directs 'Use only with adequate ventilation.'”
— WD-40
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
The published Safety Data Sheet for this product does not specify ventilation protection for consumer use.
Workplace context
29 CFR 1910.134(a); 1910.1000
“the primary objective shall be to prevent atmospheric contamination [via] accepted engineering control measures (for example, enclosure or confinement of the operation, general and local ventilation…).”
Triggered by GHS H336 on the SDS.
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
PPE tiers translate the manufacturer’s SDS and U.S. regulatory standards. Not professional safety advice. How we report safety.
This product ranks #3 of 16 in Carburetor Cleaner.
Last reviewed June 14, 2026
TL;DR A fast-evaporating aerosol that clears moderate fuel gum, carbon, and throttle-body coking in a single pass. DANGER signal word from extreme flammability plus real CNS narcosis (H336) · but no Prop 65, no toluene, no reproductive-toxicity classification. Cleaner chemistry than most carb cleaners; one can handles a typical seasonally-gummed carb or coked throttle body.
Spray short bursts into gummed carburetor passages or a throttle butterfly with the engine off. Owners and small-engine forum accounts consistently confirm single-pass clearing of moderate fuel gum and varnish, and it's well-reviewed by a large owner base; passages dry within seconds with no oily residue. Severe sitting-fuel lacquer still calls for a carb dip or ultrasonic clean.
The right pick for throttle body cleaning on fuel-injected vehicles and routine small-engine carburetor work where rubber components are in play · the absence of toluene and methanol makes it friendlier on assembled O-rings than Berryman B-12 or Gumout. Skip it for heavy long-storage varnish (B-12 remains the community choice) and for GDI intake-valve carbon deposits, which require a dedicated intake cleaner.
DANGER. SDS §2: H222 (extremely flammable aerosol), H280 (gas under pressure), H319 (eye irritation), H336 (CNS narcosis). Both H319 and H336 are health-tier H-codes · the DANGER classification reflects real biological hazard, not flammability alone. Flash point −20 °C. SDS §15 confirms no Prop 65 warning, no carcinogen or reproductive-toxicity classification. Use in a well-ventilated area; avoid eye contact. CARB compliance is a regulatory accounting result: acetone is VOC-exempt under 40 CFR 51.100(s), but absolute solvent VOC is 700·800 g/L. No aquatic toxicity data; avoid storm drain disposal.
All three are aerosol carb cleaners with DANGER signal words and high VOC. The chemistry differs in ways that matter. Berryman B-12 is the aggressive option: methanol, acetone, and toluene blend, widely regarded in small-engine forums as the strongest on severe varnish; community reports describe it as harsher on rubber diaphragms than acetone-only formulas, and it carries a Prop 65 warning. Gumout Carb/Choke is acetone-toluene with H361d reproductive-toxicity Cat 2 and a Prop 65 warning. WD-40 Specialist is the milder profile of the three: acetone-dominant with small fractions of heptane and isopropyl alcohol, NO toluene, NO methanol, NO Prop 65 warning, and NO reproductive-toxicity classification. For throttle body work and rubber-component carbs it's the lower-risk pick; for severe sitting-fuel lacquer on small engines B-12 is still the community go-to.
Yes for external surface cleaning · the formula is one of the more rubber-friendly options in the category since there's no toluene or xylene to attack elastomer plasticizers. Avoid spraying into the intake while the engine is running (the manufacturer page warns against it), and don't soak rubber boots, vacuum hoses, or plastic mass-airflow sensors. For direct-injection systems with carbon-coked intake valves, a dedicated GDI intake valve cleaner is a better tool · this product cleans the throttle plate and butterfly face, not the back side of the intake valves.
Those two facts are both true and not contradictory. CARB compliance is a regulatory accounting result: acetone is exempt from U.S. EPA and CARB consumer-product VOC counting under 40 CFR 51.100(s) because it has very low photochemical ozone reactivity. The formula's absolute solvent fraction is roughly 85·100% by mass · measured solvent emissions are in the 700·800 g/L range. The high_voc flag in CarCareTruth scoring reflects the absolute chemistry, not the regulatory accounting. The label and the SDS are both honest; they're using different VOC definitions.
Short, targeted spray application typically does not damage common carburetor rubber at standard 5·10 minute dwell times. Acetone is a relatively benign solvent for fluoroelastomer O-rings at brief exposure, and the absence of toluene, xylene, and MEK in this formula is the meaningful safety advantage versus Berryman B-12. Avoid pooling the solvent against rubber components and avoid prolonged soaks; for soaking, use a dedicated carb-dip product. ABS plastics and some painted surfaces can craze with prolonged contact · spray, don't drown.
The WD-40 Company SDS for this product was last revised on 2018-08-27 · over seven years old. WD-40 has not publicly hosted a newer revision. The 2018 SDS already claims compliance with current CARB and U.S. EPA consumer-product VOC rules, which suggests the formula did not change in the 2019·2022 reformulation wave that affected other carb cleaners. CarCareTruth's scoring uses the 2018 SDS as the authoritative source while flagging the staleness; if WD-40 issues a revision, the page will be re-scored.
Marketing copy from WD-40, via Amazon. Not editorial.
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