CarCareTruth Score
Decent, but wear gloves and ventilate.
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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 section 2 classifies the product as H319 (Cat 2A serious eye irritation), not H318. Aerosol jet spray with vapor pressure 185 mmHg generates inhalable mist that can drift toward the face during carburetor application.”
— Gumout
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 section 2 mixture classification does not include H315; section 2 'Other Information' notes mild skin irritation only. SDS section 8 lists nitrile or neoprene among acceptable glove materials for prolonged or repeated handling.”
— Gumout
U.S. regulatory standard
29 CFR 1910.1000; 1910.1200
“Each employer shall assure that no employee is exposed [in excess of the PEL]…”
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 section 2 lists H361d (suspected of damaging the unborn child) and H373 (target-organ toxicity through repeated exposure: CNS, kidney, liver) alongside H336 vapor narcosis. The DANGER signal word is co-driven by these health H-codes, not flammability alone. SDS section 8 directs an organic-vapor cartridge respirator when ventilation is inadequate; the 185 mmHg vapor pressure and toluene fraction make that the operative case in any enclosed garage.”
— Gumout
U.S. regulatory standard
29 CFR 1910.134; 1910.138; 1910.1000
“the primary objective shall be to prevent atmospheric contamination…”
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
UN GHS hazard statement
H373“May cause damage to organs through prolonged or repeated exposure”
UN GHS Rev. 9 (2021)
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 #12 of 16 in Carburetor Cleaner.Three above it ↓
Last reviewed June 17, 2026
TL;DR A category-staple aerosol that clears moderate gum and varnish from carburetor passages on the first pass and evaporates fast and clean. The DANGER signal word is earned: the SDS lists reproductive-toxicity Cat 2, target-organ toxicity through repeated exposure, and a Prop 65 warning alongside the flammability hazards. SDS section 8 directs an organic-vapor cartridge respirator when ventilation is inadequate; goggles when overhead spray is likely.
Point the straw into the carburetor throat or at the gummed linkage and spray in short bursts. The fast-evaporating solvent system dissolves varnish and fuel gum and leaves passages dry within seconds. Community evidence on small-engine and vintage motorcycle forums is consistent: one can handles a typical seasonally-gummed lawnmower or generator carb in one pass. Severely varnished carbs from long-stored fuel often need a second can or a follow-up carb dip.
The right buy for a home mechanic with a sit-started lawnmower, generator, snowblower, or vintage carbureted vehicle that just needs the seasonal gum cleared. Skip it for diaphragm carbs (CV-style motorcycle units, where the rubber diaphragms are attacked by the solvent), for fuel-injected engines (use a dedicated throttle-body cleaner), and for severely lacquered carbs that have been sitting for years (those want an ultrasonic clean or a carb dip, not an aerosol).
The signal word is DANGER and is driven by real health hazards: H361d (suspected of damaging the unborn child, toluene-driven), H373 (target-organ toxicity through repeated exposure to CNS, kidney, and liver), H319 (serious eye irritation), and H336 (vapor narcosis), alongside extreme flammability and a California Prop 65 warning. Flash point is -20 C; vapors accumulate fast in still air. SDS section 8 directs an organic-vapor cartridge respirator when ventilation cannot be achieved. The "50-state VOC compliant" label reflects the regulatory acetone exemption, not low absolute solvent emissions; absolute VOC is around 680 g/L. Overspray runoff should never reach a storm drain.
At standard 5-10 minute dwell times, community evidence on small-engine and motorcycle forums shows no consistent rubber-damage reports for typical O-rings. Prolonged soak (15+ minutes) or repeated immersion can swell some rubbers; toluene is a known plasticizer-leacher. For assembled carbs with rubber components, spray and flush in short bursts and avoid pooling the solvent against gaskets. Skip Gumout entirely on diaphragm carbs (CV-style on Japanese motorcycles); those rubber diaphragms are particularly sensitive.
No. The 50-state compliance label means the formula meets the CARB Consumer Products Regulation for carburetor cleaner aerosols, achieved primarily by relying on acetone's U.S. EPA VOC-exempt classification (40 CFR 51.100(s)). On an absolute mass basis the formula is roughly 70-95% solvent; measured VOC content is high. The label is regulatory-true and chemistry-honest at the same time; they're different definitions of VOC.
DANGER here is driven by health H-codes, not just flammability. SDS section 2 lists H361d (suspected of damaging the unborn child), H373 (target-organ toxicity through repeated exposure), and H319 (serious eye irritation Cat 2A) alongside the physical hazards. The reproductive-toxicity classification is the consequential one; it's why the Prop 65 warning calls out toluene and birth defects. Retail availability does not reflect hazard classification.
The label explicitly says 'Not recommended for fuel injected vehicles' for the inside-the-engine spray path. For external throttle body cleaning on a port-injected engine it's commonly used, but Gumout sells a separate Throttle Body Cleaner formulated to be friendlier to oxygen sensors and catalytic converters. This carb cleaner's high-solvent load is more aggressive than necessary for routine throttle-body service.
All three are aerosol carb cleaners in the same DANGER/Prop 65/high-VOC regulatory band. Berryman B-12 historically has the most aggressive solvent system and is the small-engine community favorite for severe varnish. CRC Carb & Choke is closer to Gumout in formula and label profile. Gumout's edge is brand recognition and wide retail availability; B-12's edge is varnish-busting power; CRC's edge is per-can value. For routine maintenance and moderate gum on a lawnmower or generator, Gumout is the standard pick.
Marketing copy from Gumout, via Amazon. Not editorial.
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