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Prices may varySerious hazard — read before use
The 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.
- H304 “May be fatal if swallowed and enters airways.”
GHS Category 1 aspiration toxicity — thin, oily liquids can slip into the lungs if swallowed, causing chemical pneumonia.
If swallowed, inhaled, or splashed in eyes:
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.
The Podium · Top 3 in Oil Additive
See the full ranking →This product ranks #4 of 6 in Oil Additive.Three above it ↓
CarCareTruth's Analysis
Last reviewed May 26, 2026
TL;DR Petroleum-based cleaning concentrate — the active chemistry is a hydrocarbon-based detergent blend with no ZDDP or tribological anti-wear compound. DANGER signal word is driven by an aspiration hazard at concentrate strength; do not induce vomiting if ingested — seek medical attention.
What it is and how it performs
Sea Foam Motor Treatment uses a proprietary hydrocarbon-cleaning blend to dissolve sludge, varnish, and deposits in the crankcase and fuel system. The mechanism is solvent-detergent cleaning, not anti-wear tribology. Community evidence is substantial: 4.8 stars from over 29,000 verified buyers with consistent reports of smoother idle after crankcase pre-drain treatment. No ZDDP or phosphorus compounds — no catalytic converter concerns. Compatible with gasoline and diesel engines, conventional and synthetic oil.
Who should buy this — and who should skip it
Best for owners of older or high-mileage engines who suspect sludge buildup and want a cleaning pass before an oil change — and for fuel stabilization in stored vehicles or small engines. Skip if you need a genuine anti-wear additive: Sea Foam is a cleaner, not a tribological supplement.
Safety and environmental impact
DANGER signal word from an aspiration hazard — do not induce vomiting if ingested, seek medical attention. SDS §2 classifies skin irritation (H315), eye irritation (H319), and respiratory irritation (H335) at mixture level. No Prop 65 chemicals per SDS §15. Petroleum-derived drain-destined concentrate. Used oil goes to a collection facility — not the drain.
From the manufacturer
Marketing copy from Sea Foam, via Amazon. Not editorial.
- •It works through fuel injectors and carburetors to remove harmful residues and deposits from fuel passageways, intake valves, pistons, and chamber areas.
- •It cleans harmful residues and deposits that can restrict oil flow and engine lubrication.
- •It helps fuel resist evaporation, preserves ignition vapors, adds protective lubricity, and prevents the formation of gum and varnish in fuel systems.
- •Add Sea Foam to all fuel and oil systems to help prevent common engine problems.
- •Sea Foam cleans harmful fuel and oil residues that often lead to problems like rough idle, hard starting, oil burning, and loss of power
- •Sea Foam Motor Treatment is made with 100% safe petroleum cleaning and lubricating ingredients and it does NOT contain harsh chemicals or detergents
- •Sea Foam is safe and effective in any gas or diesel engine, gasoline or diesel fuel, and conventional or synthetic motor oil.
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Manufacturer videos
Manufacturer specifications
- Manufacturer
- Seafoam
- Brand
- Sea Foam
- Model
- SF16
- Item Weight
- 1.09 pounds
- Package Dimensions
- 7.99 x 2.99 x 2.99 inches
- Item model number
- SF16
- Manufacturer Part Number
- SF16
- ASIN
- B084BRH24Y
- Customer Reviews
- 4.8 4.8 out of 5 stars (29,186) 4.8 out of 5 stars
- Best Sellers Rank
- #426 in Automotive (See Top 100 in Automotive) #4 in Fuel System Cleaners
- Date First Available
- January 30, 2020
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