ingredient investigation
A Line-by-Line Audit of Method's 'Plant-Based' Cleaning Spray
We read every ingredient in Method's all-purpose spray so you don't have to. Here's what's plant-based, what isn't, and what's missing from the label.
Calling a product 'plant-based' costs nothing and proves nothing — real transparency means publishing every ingredient with a safety score attached.
— Elizabeth Uria, PhD — Co-founder, Ecolosophy
The Label That Started This Investigation
Picture the cleaning aisle at a Target in early 2025. Sleek bottles. Friendly fonts. A little leaf icon. Method’s all-purpose spray sits right at eye level, and the front panel says — clearly, confidently — “plant-based cleaning.” A parent grabs it without a second thought, because that’s exactly what the design is engineered to produce: trust without reading.
I used to be that parent. Then I got sick.
After years of managing Crohn’s disease and learning how much the chemical load in our home environment interacts with gut and immune function, I started reading every label. Not skimming — reading. And Method, despite its genuinely better-than-average transparency reputation, left me with real questions. This article is my attempt to answer them systematically, ingredient by ingredient, with sources you can check yourself.
What “Plant-Based” Actually Means (Legally: Nothing)
Let’s start here, because the entire audit depends on it. The phrase “plant-based” on a cleaning product label is a marketing claim, not a regulatory category. The FDA has no binding definition for it. The EPA does not require any minimum percentage of plant-derived content to use the term. EWG’s own guide to healthy cleaning explicitly flags “natural” and “plant-based” as unregulated terms that manufacturers use freely and without enforcement consequence.
Compare that to EPA Safer Choice certification, which does require full ingredient disclosure, safety data for each ingredient, and third-party biodegradability testing (often the OECD 301F standard). Method’s standard all-purpose spray does not carry that certification. That gap matters enormously.
Why This Isn’t a Method-Specific Problem
To be fair to Method, they’re operating in a regulatory vacuum that affects Grove Co., Mrs. Meyer’s, Blueland, and most of the “clean” cleaning industry. No federal law currently requires cleaning product manufacturers to list every ingredient on the label. California’s Cleaning Product Right to Know Act (effective 2020) pushed some companies to be more forthcoming online, but enforcement is patchy and fragrance exemptions remain wide open.
The reason we single out Method here is precisely because they market harder on the “plant-based” claim than almost anyone else. The bigger the promise, the more carefully it deserves scrutiny.
The Ingredients, One by One
Method’s all-purpose cleaner (the standard scented spray) lists the following on their website as of early 2026: water, alcohol denat., lauryl glucoside, coco-glucoside, sodium gluconate, fragrance, methylisothiazolinone, benzisothiazolinone.
Let’s walk through the ones that warrant a conversation.
Lauryl Glucoside and Coco-Glucoside (the Good News)
These two surfactants are genuinely plant-derived — typically made from coconut or corn glucose and fatty alcohols. They’re among the mildest surfactants available, and EWG rates both as low concern. If you want to understand why surfactant sourcing matters, our deep-dive on the surfactant distinction in plant-based cleaners explains the chemistry without the jargon. These ingredients are the real justification for Method’s plant-based claim, and they deserve credit.
Fragrance (the Wildcard)
One word on the label. Potentially dozens of compounds behind it. A 2006 peer-reviewed study published in Contact Dermatitis and indexed on PubMed found that fragrance mixtures are among the most common causes of allergic contact dermatitis in consumer products, and manufacturers are not required to disclose individual fragrance compounds in the U.S. due to trade secret protections.
Method does publish some fragrance ingredient information through their website’s ingredient glossary, which puts them ahead of SC Johnson’s conventional lines. But their standard all-purpose spray fragrance is still not fully disclosed at the compound level, which means the 30–40% of the formula that constitutes the scent profile remains partially opaque.
Methylisothiazolinone (MI): The Ingredient That Earned a D
This is the one that stopped me cold. Methylisothiazolinone (MI) is a biocide preservative used to prevent microbial growth in water-based products. EWG rates it a D — the second-lowest grade — citing skin sensitization, potential neurotoxicity in laboratory settings at high concentrations, and environmental concerns including aquatic toxicity.
A 2014 peer-reviewed review in Dermatitis (indexed on PubMed, PMID 24773363) documents MI as a leading cause of contact allergy in rinse-off and leave-on products, prompting the European Scientific Committee on Consumer Safety to restrict its concentration in cosmetics. The EU’s restrictions on MI in rinse-off products took effect in 2016. The U.S. has no equivalent restriction.
For someone with a compromised immune system or inflammatory condition — and this is personal for me — a preservative with documented sensitization data is not something I want in a product I’m spraying on my kitchen counter every morning.
Benzisothiazolinone (BIT): MI’s Less-Studied Cousin
BIT is a related biocide that shares some of MI’s concerns. EWG rates it a D as well, flagging skin allergy potential and limited safety data for repeated household exposure. It’s increasingly common in products reformulated to reduce MI concentration — essentially a substitution that may not represent a genuine safety improvement.
The Audit at a Glance
| Ingredient | Plant-Derived? | EWG Score | Primary Concern |
|---|---|---|---|
| Water | N/A | A | None |
| Alcohol Denat. | Varies (often synthetic) | B | Inhalation at high concentrations |
| Lauryl Glucoside | Yes (coconut/corn) | A | None |
| Coco-Glucoside | Yes (coconut) | A | None |
| Sodium Gluconate | Yes (fermented glucose) | A | None |
| Fragrance | Partially undisclosed | D | Allergens, undisclosed compounds |
| Methylisothiazolinone | No (synthetic biocide) | D | Skin sensitization, aquatic toxicity |
| Benzisothiazolinone | No (synthetic biocide) | D | Skin allergy, limited safety data |
The math isn’t flattering: out of eight disclosed ingredient categories, two are rated D, one is rated B, and one (fragrance) conceals an unknown number of additional compounds. Three of the eight are not plant-derived by any reasonable definition. That’s a significant gap between the front-panel claim and the back-label reality.
What Genuine Transparency Actually Looks Like
I want to be clear that transparency isn’t just about what brands say — it’s about what they make verifiable. Elizabeth Uria, PhD, our co-founder and the person who formulated Ecolosophy’s concentrate line, set a non-negotiable standard when we launched: every ingredient published with its INCI name, its source (plant or mineral), its EWG score, and its biodegradability status.
That’s not because we want a gold star. It’s because after watching the “natural” cleaning industry make the same unenforceable promises for a decade, we decided the only honest move was radical specificity.
If you want to understand what the broader landscape of ingredient obfuscation looks like — not just in Method but across the category — our article on hidden toxins in cleaning products covers the systemic problem in more depth.
And if you’re wondering whether non-toxic cleaners actually work or whether you’re trading cleaning power for a clear conscience, the answer is more nuanced than you’d expect — do non-toxic cleaners work breaks it down with actual performance data.
What To Do With This Information
This audit isn’t a reason to panic about the Method spray under your sink, and it’s not a verdict that Method is a bad company — they genuinely publish more than most. But it is a reason to raise your baseline for what “plant-based” means before you spend money on it.
Here’s the practical next action: before you buy any cleaning product marketed as natural, plant-based, or green, look it up on EWG’s Guide to Healthy Cleaning (ewg.org/guides/cleaners) before you reach for your wallet. Takes 45 seconds. If the product scores a C or lower, or if “fragrance” appears without further disclosure, treat the front-label claim as aspirational rather than accurate.
If you want a starting point for comparison, the EPA Safer Choice product search (epa.gov/saferchoice) lists every certified product — none of which can use the label without disclosing full ingredients and passing biodegradability testing. That’s the bar worth shopping toward.
Your home, your body, and — if Crohn’s has taught me anything — your immune system deserve ingredients you can actually look up.
Sources cited
- EWG Skin Deep — Method All-Purpose Cleaner — EWG rates Method All-Purpose Cleaner a C overall, with individual ingredient concerns flagged for methylisothiazolinone and fragrance.
- EPA Safer Choice Program — What the Label Means — EPA Safer Choice requires full ingredient disclosure and third-party biodegradability testing; Method's standard spray does not carry this certification.
- NIH PubMed — Methylisothiazolinone skin sensitization review — Peer-reviewed dermatology literature documents methylisothiazolinone as a leading cause of contact allergy in leave-on and rinse-off consumer products.
- NIH PubMed — Fragrance allergens in consumer products — Study found fragrance mixtures are among the most common causes of allergic contact dermatitis, with manufacturers not required to list individual compounds.
- EWG Guide to Healthy Cleaning — Understanding 'Natural' and 'Plant-Based' Claims — EWG notes that 'natural' and 'plant-based' are unregulated marketing terms with no enforceable legal standard in the U.S. cleaning products industry.
Frequently asked
Is Method cleaner actually plant-based?
Method uses several plant-derived surfactants, but also includes synthetic preservatives like methylisothiazolinone and proprietary fragrance compounds that are not plant-derived. 'Plant-based' has no legal definition in cleaning products, so the claim is partially accurate at best.
Is Method safe for people with sensitive skin or autoimmune conditions?
Possibly not for everyone. Methylisothiazolinone, found in some Method formulas, is a documented skin sensitizer. If you have Crohn's, eczema, or contact dermatitis, check EWG's Skin Deep database for the specific product before buying.
Does Method disclose all its ingredients?
Method discloses more than many conventional brands, but fragrance compounds are still listed as a single word — 'fragrance' — which can mask dozens of undisclosed chemicals. They do not hold EPA Safer Choice certification for their standard spray.
What should I look for instead of 'plant-based' on a label?
Look for EPA Safer Choice certification, a full ingredient list with INCI names, fragrance-free or fully disclosed fragrance, and third-party biodegradability data like an OECD 301F test result.
Are there Method products that are safer than others?
Yes. Method's fragrance-free and baby-line products generally score better on EWG. But the standard scented all-purpose spray consistently earns a C or lower due to preservative and fragrance concerns.
