Wash & detailing
Is Simple Green Toxic? What the SDS Actually Says
Whether Simple Green is toxic depends on which one you grabbed. The original green all-purpose cleaner is about as tame as a cleaner gets: no hazard classification on its Safety Data Sheet, no signal word, EPA Safer Choice certified, zero measured VOC. It does carry a California Prop 65 warning. Its SDS names no listed chemical, so the warning is not tied to a disclosed hazard, though the ethoxylated surfactant can carry trace ethylene oxide or 1,4-dioxane, which is the likely reason. Either way it is a low-level precaution, not a poison. The heavy-duty Pro HD is a different animal: it earns a WARNING label for eye irritation (H320) and a Prop 65 warning for a real trace carcinogen, diethanolamine. Use the regular stuff for most jobs, save Pro HD for baked-on grease, and keep the concentrate out of your eyes.
What Is Simple Green?
You already know the bottle. That green stuff on the shelf of half the garages in America, the one that says non-toxic and biodegradable right on the front. That promise is exactly why this page exists. "Non-toxic" is a marketing word, not a regulated one, so the only honest way to answer the question is to read the manufacturer's own Safety Data Sheet.
There is a catch that trips up most people: there are two Simple Greens. The regular green all-purpose cleaner and the heavy-duty Pro HD are different formulas with different hazard data, so "is it toxic" has two answers. If you are shopping the wider field, our all-purpose cleaner picks and engine degreaser picks cover the alternatives.
What the Safety Data Sheet Says
These verdicts come from the hazard codes and GHS classifications in the manufacturer's Safety Data Sheets, not from CarCareTruth's opinion. The original green formula is about as mild as an SDS gets, and even the Pro HD stays well short of a solvent-heavy degreaser.
GHS Hazard Classification
The two formulas classify nothing alike.
The original Simple Green Industrial Cleaner and Degreaser carries no GHS hazard classification at all. No signal word, no pictograms, no H-codes, and the SDS states it is not hazardous under the 2012 OSHA Hazard Communication Standard (Source: Sunshine Makers SDS, Section 2). It is also EPA Safer Choice certified, which is a real ingredient-by-ingredient vetting, not a badge a company hands itself.
The Simple Green Pro HD earns a WARNING signal word and one code:
- H320 (causes eye irritation): the concentrate can irritate eyes on a splash or spray-back. It is reversible, and the SDS notes no pictogram is required (Source: Simple Green Pro HD SDS v13421-24A, Section 2).
Neither one is flammable, acutely toxic, or a breathing hazard. Both are water-based.
Key Ingredients
The original is short and plain: water, a nonionic alcohol-ethoxylate surfactant, a chelator to help it work in hard water, and a pH buffer. And the ingredient everyone still ties to Simple Green, 2-butoxyethanol (butyl cellosolve), is not on the current sheet for this formula.
The Pro HD is built to cut heavier grease, and the ingredient list shows it. Alongside water and the same surfactant family, its SDS lists triethanolamine as an alkaline builder, propylene glycol butyl ether as its solvent (the lower-toxicity propylene-glycol cousin of 2-butoxyethanol, not the real thing), and a trace of diethanolamine that drives its Prop 65 warning. The percentages are trade-secret ranges.
What It Actually Does to Skin, Eyes, and Lungs
For the original, there is barely anything to report. The SDS lists every bit of its protection guidance as conditional: safety glasses if splashing is likely, gloves for prolonged use, ventilation for small enclosed spaces. None of it is driven by a classified hazard, because there isn't one. Section 9 puts the VOC at zero.
The Pro HD is where the eyes matter. Section 8 calls for glasses or goggles where splash or spray-back is likely, which is what the H320 rating is about, and gloves for the concentrate because of the alkaline pH of 10 to 11.5, not because of any skin-irritation code, since there is none. The VOC is a low 20 grams per liter, and it is non-flammable.
The Main Risk Pathways for Car Owners
With the original, the risks are boring and mechanical. Splash the concentrate in your eye and it will sting. Rinse it. Scrub bare-handed all afternoon and the alkalinity dries your skin. Dilute it for normal use and even that fades. There is no real fire or breathing pathway.
With the Pro HD, it is your eyes. Blast concentrate into an engine bay at face height and some of it comes right back at you, which is the exact scenario behind the H320 code and the goggle line in Section 8. Wear the goggles for that one. The higher alkalinity also makes the mist more irritating to breathe, so ease off the trigger in tight spaces.
For pets and kids, either formula, the concern is a mouthful of wet concentrate: an upset stomach and an irritated mouth or eyes, not the way antifreeze poisons a dog. Let surfaces dry, rinse food bowls with plain water, and keep the concentrate closed and out of reach.
One caveat detailers know that has nothing to do with health: like most alkaline cleaners, the original at full strength, or left to dwell and dry, can dull or stain bare and polished aluminum, think a polished intake or aluminum trim in the bay. It is a cosmetic surface issue, not a toxicity one, and it goes away if you dilute it, keep it moving, and wipe or rinse before it flashes dry.
What the SDS Does NOT Flag
It is just as fair to say what the sheets do not flag. Neither formula carries an acute-toxicity code for swallowing, skin, or breathing. Neither is corrosive, a respiratory sensitizer, or flammable. The original carries no cancer or reproductive code, and even the Pro HD's cancer concern is a Prop 65 label for a trace ingredient, not an H350 classification on the SDS itself.
The one word not to over-read is "non-toxic." It is fair for the original in the everyday sense, and the SDS backs that. It does not mean splash it in your eyes, and it does not mean the Pro HD is the same bottle.
Safer Choices and Product Context
Want the lower-hazard option for a job that does not need extra muscle? The original Simple Green Industrial Cleaner and Degreaser, diluted, is the pick. Move up to Simple Green Pro HD only when you need it, and wear eye protection for the concentrate. For the wider field, see our all-purpose cleaner and engine degreaser pages, and the ingredient library for plain-English breakdowns of anything on a label.
Sources and SDS Reference
- Sunshine Makers, Inc. (Simple Green) Safety Data Sheet, Simple Green Industrial Cleaner and Degreaser, revision 2024-03-12, Sections 2, 3, 8, 9, 11, and 15.
- Sunshine Makers, Inc. Safety Data Sheet, Simple Green Pro HD Heavy Duty Cleaner and Degreaser, version 13421-24A, issued 2024-06-12, Sections 2, 3, 8, 9, 12, and 15.
- U.S. EPA Safer Choice program product listing (original Industrial Cleaner and Degreaser).
- CarCareTruth chemicals library and hazard-code library for the plain-English ingredient and H-code references linked above.
Frequently asked questions
Is Simple Green really non-toxic like the bottle says?
For the original green formula, mostly yes, and the SDS backs it: no hazard classification, no signal word, EPA Safer Choice certified, zero VOC. Two things keep it from being a total free pass. 'Non-toxic' is a marketing word with no regulated meaning, and the concentrate is still alkaline enough to sting eyes and dry out skin. And it is the bottle that is low-hazard, not the brand. The heavy-duty Pro HD is a different formula with a WARNING label. Read the label in your hand, not the name on it.
Why does Simple Green have a Prop 65 warning if it is non-toxic?
The two formulas carry it for different reasons. On the original, the SDS names no California Prop 65 chemical in its disclosed ingredients, so the warning is not tied to a listed hazard on the sheet. The likely trigger is the surfactant: alcohol ethoxylates can carry trace ethylene oxide or 1,4-dioxane, both Prop 65 carcinogens, at levels too low to disclose. Treat that as a low-level precaution rather than proof of a poison. On the Pro HD it is concrete: Section 15 lists diethanolamine, a chemical California calls a carcinogen, at under 0.01 percent. A Prop 65 label by itself does not tell you which of those two situations you are in.
Does Simple Green contain 2-butoxyethanol or butyl cellosolve?
Not on the current Safety Data Sheet for the original green all-purpose cleaner. Its listed ingredients are water, a nonionic surfactant, a chelator, and a pH buffer. This is the ingredient people still tie to Simple Green from years of forum talk, so it is worth saying flat out: it is not on the sheet we reviewed. The Pro HD uses a different glycol-ether solvent, propylene glycol butyl ether, which is the lower-toxicity propylene-glycol cousin, not 2-butoxyethanol.
Is Simple Green safe to breathe?
For the original, yes for normal use. The SDS lists no inhalation-toxicity code and zero VOC, so there is no solvent vapor to build up, and Section 8 only asks for ventilation in small enclosed spaces. The one way to make any cleaner unpleasant to breathe is to fog it as a fine mist, so ease off the trigger and open a door when you clean inside a cabin. The Pro HD is also low-VOC and non-flammable with no inhalation code, but its higher alkalinity makes the mist more irritating.
Is Simple Green safe on your hands and skin?
The original carries no skin-irritation or corrosive code, and brief contact at working dilution is low-risk. Like any alkaline cleaner it will strip oils and dry your hands on long or repeated contact, which is why Section 8 suggests gloves for extended use. The Pro HD concentrate is more alkaline, pH 10 to 11.5, and its SDS calls for gloves when you handle it neat. Rinse splashes off, and glove up for long sessions or for undiluted concentrate.
Is Simple Green toxic to dogs and cats?
Not the way antifreeze is, no. The original is not classified as acutely toxic and it rinses clean, which is why people use it around pets, but no cleaner is meant to be licked up wet. Worst case from lapped-up concentrate is a sour stomach and an irritated mouth, made a bit worse by the alkalinity. Let surfaces dry, rinse food and water bowls with plain water, and keep the concentrate closed and out of reach. If a pet swallows some, call your vet or the ASPCA Animal Poison Control Center at 888-426-4435.
Is Simple Green Pro HD the same as regular Simple Green?
No, and that is the whole point. Different formulas, different safety data. The regular green cleaner has no GHS classification, no signal word, and EPA Safer Choice certification. The Pro HD carries a WARNING signal word, the H320 eye-irritation code, a higher pH of 10 to 11.5, and a Prop 65 warning for trace diethanolamine. Pro HD cuts heavier grease and it works, it just wants eye protection and more careful handling. Check the product name, not just the brand.
Which Simple Green is best for detailing, and how do you mix it?
For interior wipe-downs, door jambs, wheel wells, floor mats, and light grime, the original green Industrial Cleaner is the lower-hazard pick. Mix it to the job: Simple Green's own label runs from about 1:10 for heavy degreasing down to 1:30 for light cleaning, and a greasy engine bay wants closer to 4:1. One habit that matters, do not let it dry on the surface. It can streak glass and haze bare aluminum, so work in sections and wipe or rinse before it flashes off. Reach for Pro HD only when the regular formula will not cut it, and wear eye protection for the concentrate.