How We Score Products

The CCT Score is our headline rating — a composite “would I recommend this?” number on a 1–10 scale. It blends four weighted components:

Effectiveness (45%)

The editorial heart of the score: “Does the product do what it claims?” We score effectiveness within a product’s category — comparing a ceramic spray to other ceramic sprays, not to a bucket.

Data sources (priority order): SDS/TDS active-ingredient analysis, Amazon verified-purchase sentiment (trailing 12 months weighted 2×), detailing community consensus (r/AutoDetailing, Autogeek, DetailingWorld), and manufacturer claims (treated as hypotheses, not evidence).

A product cannot score above 7.0 on manufacturer claims alone — at least one external corroborating source is required for higher scores.

Value (25%)

Value is price-per-userelative to the category median, not sticker price. We estimate applications per container (dilution ratios for concentrates, panels per kit for coatings, wash cycles for towels) and compare cost-per-application to peers. A product at category-median cost scores 5.0; each 20% cheaper adds +1.0, each 20% more expensive subtracts −1.0.

Community & Amazon Adjustments

After computing the base composite, two small adjustments keep the score grounded in real-world feedback:

• CarCareTruth community: ±0.3 max (requires 3+ rated comments)
• Amazon rating signal: ±0.2 max (Bayesian-smoothed with 50-review prior)

These adjustments keep community voice present without letting a handful of reviews dominate the editorially-computed score.

Confidence Levels

The Health Score (1–10, one decimal) reflects realistic risk to a home detailer — not industrial worst-case, not regulatory theater. We start at 10.0 and deduct for identified hazards using publicly available SDS and GHS data.

Deduction-Based Method

“Start high, deduct” makes the score explainable: each line item corresponds to a verifiable data point you can check against the product’s SDS.

Tier 1 — Critical risks (max −6.0)

• GHS Signal word DANGER: −2.0
• H330 (fatal if inhaled): −3.0
• H334 (respiratory sensitizer) or confirmed asthmagen: −2.5
• H314 (skin corrosion/burns): −2.0
• H318 (serious eye damage): −1.5
• Contains PFAS: −2.0
• Prop 65 warning on label: −1.5
• H350 (carcinogen Cat 1): −2.0 — hard cap at 4.5

Tier 2 — Major risks (max −4.0)

• Signal word WARNING: −0.5
• H317 (skin sensitizer): −1.0
• H335 (respiratory irritation): −0.75
• H315/H319 (skin/eye irritation): −0.3 each
• High VOC: −1.0 (additional −0.5 if ≥500 g/L)
• Extreme pH (≤2 or ≥12.5): −1.0

Tier 3 — PPE burden (max −2.0)

• Respiratory PPE required: −1.5
• Respiratory PPE recommended: −0.5
• Eye/skin PPE required: −0.25

Form Factor & Concentration

Aerosols cap at 9.0 (inherent inhalation vector). Sprays apply lung-related deductions at 1.25×. Ingredient concentration modulates deductions: <1% halves the penalty, >10% increases it by 25%.

Bonuses & Hard Caps

EPA Safer Choice certification adds +0.5. No GHS signal word adds +0.3. Products confirmed carcinogenic (H350) cannot exceed 4.5; respiratory sensitizers (H334) cannot exceed 5.5.

Score Labels

The Environment Score (1–10, integer) reflects realized environmental impactfrom typical consumer use. Design principle: harm = (intrinsic toxicity × persistence) × exposure pathway.

Baseline & Pathway Modifier

Every chemical starts at 7.0. Rinse-off products (car wash soaps, wheel cleaners, degreasers) multiply all deductions by 1.25× because they enter waterways directly. Leave-on products (coatings, sealants, dressings) multiply by 0.75×.

Deductions

Bio-persistence

• Contains PFAS: −3.0 (hard cap: max score 3)
• Bioaccumulative ingredient: −1.5 per compound (max −3.0)
• Persistent non-PFAS ingredient: −1.0 per compound (max −2.0)
• Ozone-depleting substance: −2.0 (hard cap: max score 4)
• Microplastic ingredient: −1.5 per ingredient (max −2.5)

Aquatic toxicity

• Product-level aquatic toxic flag: −1.5
• Per-ingredient aquatic toxicity: −1.0 each (max −2.0)

VOC load

• 0–50 g/L: no deduction
• 51–150 g/L: −0.5
• 151–350 g/L: −1.0
• 351–550 g/L: −1.5
• >550 g/L: −2.0

Credits (Positive Attributes)

• EPA Safer Choice: +2.0
• Product-level biodegradable: +1.0
• All ingredients biodegradable: +0.5 (stacks)
• CARB compliant: +0.5
• Waterless/rinseless formulation: +1.0

Score Labels