Royal Purple Maxfilm Synthetic Penetrating Lubricant
Priced as of May 22, 2026
4.8(450 ratings)Buy on AmazonSaved to your guest loadout. Sign up to also save to your Cabinet (consumables) or Kit (tools you own).
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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.
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.
From the Safety Data Sheet
Full SDS ↗ (rev. 2022-12-14)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.
EyesSituationalMfr. SDS §8SkinRecommendedMfr. SDS §8 · 29 CFR 1910.138(a) · GHS H317LungsSituationalMfr. SDS §8 · 29 CFR 1910.1200(f) · GHS H304Ventilation—No PPE in published sourcesShow details for all categories ▾Hide details ▴
From the manufacturer’s Safety Data Sheet, Section 8
“No H318 or H319 in SDS §2 mixture classification. Aerosol mist near face level is the primary eye exposure pathway.”
— Royal Purple
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
“H317 (Skin Sensitization Cat 1) confirmed in SDS §2 mixture classification — repeated dermal contact warrants protection.”
— Royal Purple
U.S. regulatory standard
29 CFR 1910.138(a); 1910.132(d)
“appropriate hand protection when employees' hands are exposed to hazards such as those from skin absorption of harmful substances.”
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
“Aerosol form factor creates fine mist near face level. H335 absent from §2 mixture classification; enclosed-space aerosol mist is the inhalation exposure trigger.”
— Royal Purple
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.
The Podium · Top 3 in Penetrating Oil / Multi-Purpose Lubricant
See the full ranking →This product ranks #6 of 11 in Penetrating Oil / Multi-Purpose Lubricant.Three above it ↓
CarCareTruth's Analysis
Last reviewed May 26, 2026
TL;DR DANGER-rated aerosol with a Prop 65 warning — the SDS classifies an aspiration hazard if swallowed and a skin sensitization risk from the carrier. Amazon verified-purchase reviewers (4.8★, 450 reviews) confirm reliable penetration on light-to-moderate rust in 10–20 minutes and above-average re-seizure protection from the named synthetic additive package.
What it is and how it performs
Maxfilm wicks a synthetic petroleum carrier into corroded threads to break the rust's grip. Amazon reviewers (4.8★, 450 reviews) report penetration on light-to-moderate rust in 10–20 minutes from a single application; heavy rust typically requires a second coat. The disclosed corrosion inhibitor and antiwear additive package — both named in the SDS — stand out from standard petroleum-only competitors and support re-seizure protection above the category median. Royal Purple claims ASTM B117 100+ hour salt-spray protection on the manufacturer page; no independent replication was found.
Who should buy this — and who should skip it
A solid choice for a homeowner with occasional stuck fasteners who wants a synthetic formula with more residual corrosion protection than a straight petroleum-carrier spray. Skip it for frequent enclosed-space use — DANGER classification and a confirmed Prop 65 warning are documented SDS hazards that compound with repeated aerosol exposure.
Safety and environmental impact
DANGER driven by an aspiration hazard if swallowed and skin sensitization from the carrier. Do not induce vomiting if ingested — seek medical attention. Skin sensitization (H317) at the mixture level in SDS §2; SDS §8 specifies gloves for repeated contact. Aerosol mist in enclosed spaces is the primary inhalation pathway — no H335 respiratory irritation code appears at the mixture level. Prop 65 warning on the Amazon listing.
Environmental: petroleum-distillate carrier, not readily biodegradable, two aquatically toxic ingredients, one bioaccumulative ingredient per SDS §12.
Frequently asked questions
How long should I let Maxfilm dwell before trying to turn a rusted bolt?▾
Amazon verified-purchase reviewers (4.8★, 450 reviews) consistently report penetration on light-to-moderate rust in 10–20 minutes with a single application. For heavily corroded fasteners, most reviewers apply a second coat after the first dwell period and allow an additional 15–30 minutes before attempting removal.
Is Maxfilm safe on rubber seals and plastic?▾
Royal Purple's product page does not publish a compatibility list for rubber or plastics. The petroleum-distillate carrier can swell or degrade some rubber compounds and certain plastics with prolonged contact. Avoid saturating rubber boots, seals, or plastic clips — direct the straw precisely and wipe away overspray.
Why does Maxfilm carry a DANGER rating and Prop 65 warning?▾
The SDS §2 mixture classification lists H304 (aspiration hazard if swallowed) and H317 (skin sensitization). DANGER is driven by those two classifications. The Prop 65 warning appears on the Amazon listing; petroleum-distillate carriers with trace aromatic content are a common trigger even when named substances fall below individual reporting thresholds.
What makes this synthetic rather than a standard mineral-oil penetrant?▾
The formula uses a synthetic base oil and includes named additives — a corrosion inhibitor and an antiwear agent — that are disclosed in the SDS. Most commodity penetrating oils use straight petroleum-distillate carriers without a disclosed additive package.
From the manufacturer
Marketing copy from Royal Purple, via Amazon. Not editorial.
- •Fit type: Vehicle Specific
- •Flash point: 60 degrees_celsius
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Manufacturer specifications
- Material
- Synthetic
- Brand
- Royal Purple
- Package Information
- Can
- Liquid Volume
- 325 Milliliters
- Item Weight
- 9.6 ounces
- Brand Name
- Royal Purple
- Recommended Uses For Product
- Lubricant
- Specific Uses For Product
- Loosening stuck and rusted parts, Lubricating power tools, Protecting metal components in storage, Metal cutting fluid
- Item Form
- Spray
- Global Trade Identification Number
- 00641330050008, 10641330050005
- Manufacturer
- Royal Purple
- Unit Count
- 11.0 Ounce
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Top Amazon review
↗External — Amazon's most-helpful review for context.
Best lubricant in a can
This is the best lubricant I'd found in a can. It penetrates into crevices to oil the thing you're actually wanting to oil instead of just the outside. This can last a while, you don't need to use much.