CarCareTruth Score
Decent, but it's tough on the environment.
Opens Amazon in a new tab. No account needed to look.
Saved to your guest loadout. Sign up to also save to your Cabinet (consumables) or Kit (tools you own).
As an Amazon Associate I earn from qualifying purchases. Full disclosure
Prices may varyThe manufacturer's Safety Data Sheet classifies this product with one or more GHS Category 1 health hazards — the most severe tier. The hazard statements in quotes below are the verbatim GHS language from the SDS, as required by OSHA's Hazard Communication Standard. The line under each statement translates the GHS classification into plain language.
GHS Category 1 aspiration toxicity — thin, oily liquids can slip into the lungs if swallowed, causing chemical pneumonia.
GHS Category 1 eye damage — classified as causing irreversible eye damage on contact.
If swallowed or splashed in eyes:
The aspiration hazard (H304) is about the liquid being swallowed and reaching the airway, not about breathing fumes during normal use.
Call Poison Control immediately at 1-800-222-1222 (US, 24/7, free) and have the product container with you. Poison Control's standing guidance is to not induce vomiting after chemical exposure; they will direct first-aid steps based on the specific product.
About 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.
Show details for all categories ▾Hide details ▴
Translated from the manufacturer’s Safety Data Sheet, Section 2
SDS §2 classifies H318 (causes serious eye damage, Cat 1 · permanent injury risk). Hard escalation to required.
U.S. regulatory standard
29 CFR 1910.133(a)(1); 1910.151(c)
“The employer shall ensure that each affected employee uses appropriate eye or face protection when exposed to eye or face hazards from… liquid chemicals, acids or caustic liquids…”
ANSI Z87.1 (chemical splash protection — 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.
Translated from the manufacturer’s Safety Data Sheet, Section 2
SDS §2 classifies H315 (skin irritation) and H317 (skin sensitizer Cat 1). Both codes present · recommended tier (H315 + H317 combination).
U.S. regulatory standard
29 CFR 1910.138(a)
“appropriate hand protection when employees' hands are exposed to hazards such as those from… chemicals which produce an adverse effect on the skin or eyes…”
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.
Only when: in enclosed space
Beyond SDS: translated from the ingredient chemistry
No inhalation H-code in SDS §2 at mixture level (H335 appears only at §3 ingredient level for the aminoalkyl component). Flash point 71°C confirms volatile carrier · lungs key not omitted. Editorial override: pouring outdoors at a gas station involves minimal inhalation exposure; pouring in an enclosed garage concentrates vapors.
U.S. regulatory standard
29 CFR 1910.1200(f); 1910.132(d)
“The employer shall assess the workplace to determine if hazards are present, or are likely to be present, which necessitate the use of personal protective equipment.”
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.
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.
Scope of these PPE tiers. The tiers on this page translate the product's Safety Data Sheet where one is published, plus its ingredient chemistry, into a comparable rating. They describe a formulation, not a situation: a tier is not a safety determination for any specific user, task, quantity, or environment. The manufacturer's label and use instructions govern how the product is handled. Where the product is used at work, the employer's PPE program and hazard assessment under 29 CFR 1910.132 decide what protection is selected, not this page.
No warranties. CarCareTruth makes no warranties, express or implied, and expressly disclaims the implied warranties of merchantability and fitness for a particular purpose.
This product ranks #12 of 16 in Fuel Injector Cleaner.Three above it ↓
Last reviewed June 28, 2026
TL;DR DANGER signal word and H318 serious eye damage · can cause permanent injury: wear safety goggles when pouring. PEA chemistry confirmed from the US SDS, credibly targeting injectors and intake valves; combustion-chamber coverage is the brand's claim only. Well-reviewed by owners, with a broadly positive reputation.
STP Ultra 5-in-1 uses polyetheramine (PEA) · the detergent class with the most independent research on injector and intake valve deposit removal · confirmed directly from the US SDS. Co-active chemistry the brand doesn't publicly name covers combustion chambers, according to the manufacturer. One 12 oz bottle treats up to 35 gallons; pour the full bottle into a tank that's at least half-full, every 4,000 miles. Community ratings are broadly positive and the product is well-reviewed by a large owner base; no SAE paper or independent dyno test found for this specific product.
Best for gasoline-engine owners who run non-Top Tier certified fuel and want a maintenance dose of confirmed PEA chemistry on a 4,000-mile schedule. Skip it if you consistently run Top Tier gasoline · that OEM detergent package already handles prevention. Skip it for misfires, rough idle, or confirmed injector failure beyond typical deposit buildup · a pour-in product is not a substitute for professional ultrasonic cleaning.
DANGER signal word driven by H304 (aspiration hazard Cat 1) and H318 (serious eye damage Cat 1 · permanent injury risk). Do not induce vomiting if ingested · seek medical attention. Wear safety goggles; skin contact warrants nitrile gloves given the H317 skin sensitizer classification. The product combusts in the engine · exhaust byproducts are the environmental endpoint.
Marketing copy from STP, via Amazon. Not editorial.
Weekly pick
One product, one safety verdict, every week. No spam.
Chevron
Techron Concentrate Plus Complete Fuel System Cleaner
Gumout
Multi-System Tune-Up
Red Line
SI-1 Complete Fuel System Cleaner
Rislone
Hy-per Fuel Heavy Duty Injector Cleaner
As an Amazon Associate I earn from qualifying purchases. Full disclosure
Community
0 postsShare how you use this product
Drop a quick comment or post a full review with photos and a star rating.
Sign in to postNew here? Create a free account.