Permanent Hair Dye
Oxidative permanent hair colour applied at home or salon.
74Low burden · out of 100
Cleaner swapHenna, semi-permanent dyes, or less frequent application in a ventilated space
How this score is built
- 100Start
- 86.2Chemical hazard 3 × 4.6−13.8
- 79.4Everyday exposure 2 × 3.4−6.8
- 74Persistence 2 × 2.6−5.2, then rounded to 74
- LowThe band74 sits in 60–79.
What each input rests on
| Input | Rating | Evidence |
|---|---|---|
| Chemical hazard | 3/10 |
|
| Everyday exposure | 2/10 | unsourced input |
| Persistence | 2/10 | unsourced input |
Ratings are editorial. A study listed here supports the rating; it did not compute it. How the index is built
What this means for you
Permanent dyes contain aromatic amines absorbed through the scalp. Spacing out applications and good ventilation reduce the dose.
Evidence strength: moderate
See where your whole exposure load is highest — free Exposure Score →This entry and the whole Index, on your phone.
