How We Score
Our methodology is transparent, source-cited, and grounded in the same scientific databases used by regulators worldwide — applied without commercial influence.
Our Principles
Precautionary Principle First
If credible scientific evidence raises concern about a substance — even without a definitive ban — we flag it. We do not wait for regulatory consensus, which is frequently delayed by commercial lobbying.
No Industry-Funded Safety as Sufficient
We are aware of the documented phenomenon of 'agency capture' (Lang & Millstone, Nature Food, 2023). A substance being 'GRAS' or FSA-approved does not automatically make it safe in our assessment.
400+ Toxin Database
Every analysis is pre-screened against our curated ToxinDatabase of over 400 substances, cross-referenced against IARC, EFSA, REACH, Prop 65, EWG, and WHO classifications.
AI-Assisted, Human-Curated
Our AI applies our published rule set to analyse ingredients. The underlying standards — which substances are flagged and why — are set by us and grounded in the scientific literature cited here.
The Scoring Scale
Avoid At All Costs
Contains known carcinogens, hormone disruptors, or substances banned in multiple jurisdictions.
Only If Nothing Else Available
Multiple synthetic or high-concern ingredients. Significant regulatory red flags.
Proceed With Caution
Mainstream products with synthetic chemicals, preservatives, or artificial additives.
Good, But Not Perfect
Mostly natural with minor questionable additives or industrial processing.
Excellent — You Can Trust It
Only pure organic, certified natural, or zero-synthetic-material products reach this band.
Our Scientific Sources
Every flagged ingredient in our ToxinDatabase is referenced against one or more of the following authoritative bodies. When you see a source cited in your Toxin Checker results, this is where it comes from.
IARC Monographs
SourceInternational Agency for Research on Cancer
WHO body that classifies substances by carcinogenic risk. Group 1 = known carcinogen. Group 2A = probable. Group 2B = possible.
EFSA
SourceEuropean Food Safety Authority
The EU's independent food safety body. We cross-reference EFSA opinions on additives, pesticides, and contaminants.
REACH / EU Cosmetics Regulation
SourceRegistration, Evaluation, Authorisation & Restriction of Chemicals
EU regulatory framework governing chemical safety. We flag any substance restricted or banned under REACH or the EU Cosmetics Regulation.
California Prop 65
SourceSafe Drinking Water and Toxic Enforcement Act
California's list of chemicals known to cause cancer, birth defects or reproductive harm. One of the most comprehensive chemical hazard lists in the world.
EWG
SourceEnvironmental Working Group
Independent US research organisation whose Skin Deep and Food Scores databases rank ingredient safety across cosmetics, food and household products.
WHO
SourceWorld Health Organisation
Global health authority whose dietary guidelines, contaminant thresholds and carcinogen classifications form part of our baseline standards.
A Note on Transparency
JOHA is not a registered laboratory, government body, or peer-reviewed journal. We are an independent consumer information service applying a strict, publicly documented standard derived from the world's leading regulatory and scientific databases.
Our Toxin Checker uses AI to apply our published rule set at scale. The AI does not invent standards — it applies the ones documented on this page. When we cite IARC Group 1 or EFSA restrictions, those citations are real and verifiable.
We believe consumers deserve the same rigour that regulators claim to apply — without the commercial conflicts of interest that peer-reviewed research has documented within those regulatory bodies themselves.
Key reference: Lang, T. & Millstone, E. (2023). "UK food policy needs fundamental reform." Nature Food, 4, 8–11. DOI: 10.1038/s43016-022-00659-5