The highest weight is for developmental effects on the basis that these can occur at very low doses and are irreversible.
How does Million Marker Score Ingredients?
Million Marker's ingredient scoring system begins with identifying:
- 1
The authoritative chemical name.
- 2
CAS# (unique identifier) for each ingredient listed on the product label.
Chemical hazard ratings are then obtained for each ingredient, with scores possible in 11 different health categories.
Cancer
Known or suspected to increase cancer risk in humans.
Endocrine disruption
May alter hormone function and contribute to chronic diseases and disorders.
Reproductive toxicity
May alter hormone function and harm reproduction.
Developmental toxicity
May impact fetal development and birth outcomes.
Genotoxicity
May cause mutations or damage DNA in cells.
Neurotoxicity
May impact brain function or development.
Organ system toxicity
May cause organ damage and disease.
Immunotoxicity & Allergens
May impact immune system function or cause allergic reactions.
Respiratory toxicity & Asthmagens
May damage the lungs or trigger asthma.
Irritant
May cause skin, eye, or respiratory irritation.
Ecotoxicity
May be toxic to ecosystems and wildlife.
Low health concerns
Current research suggests ingredient may be safe for use.
Hazard ratings come from:
- US Environmental Protection Agency CompTox Database
- California Safe Cosmetics Program (CSCP) Product Database
- US National Library of Medicine PubChem Database
Each of these provides hazard ratings based on dozens of other sources of information on hazardous chemicals. A strength-of-evidence hierarchy is applied to hazard data, with authoritative sources prioritized over screening-level data and QSAR (Quantitative Structure-Activity Relationship) predictions.
Ingredients that do not have hazard ratings from any of these sources, and that have been identified as using safer chemistries based on the principles of the US Environmental Protection Agency Safer Choice database, are assigned a low hazard rating. If an ingredient can introduce harmful contaminants, such as ethoxylated chemicals or formaldehyde-releasing preservatives, we apply a contaminant-specific multiplier to the hazard score to account for those risks.
We then assign a weight to each health category.
The next highest weighted categories are carcinogens, endocrine disruptors, reproductive toxicants, genotoxic chemicals, and neurotoxic chemicals.
This is followed by organ system, immune, and respiratory toxicants, which are given moderate weight, as data often comes from high-exposure contexts like workplaces or in laboratory animals.
Lower weights are applied to the categories of irritants and ecotoxicity because the effects of irritants are typically temporary, and ecotoxic effects impact the environment, not people directly.
The weighted average hazard ratings in all health categories are then normalized to a 0–100 scale to produce the final Ingredient Score.
STOP (<80)
Higher concern
SLOW (80–89)
Moderate concern
GO (90–100)
Lower concern