Korean: 산성적색51호 · Functions: colorant, hair dyeing
No specific rule on file.
Prohibited Annex II/1337
Conditions: 2',4',5',7'-Tetraiodofluorescein, its disodium salt (Acid Red 51; CI 45430) and its aluminium salt (Pigment Red 172 Aluminium lake) when used as a substance in hair dye products
Source: EU CosIng — Annex II · checked Oct 16, 2026
Approved colorant Annex IV/80
Conditions: Disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate and its insoluble barium, strontium and zirconium lakes, salts and pigments
Required label warning: Purity criteria as set out in Commission Directive 95/45/EC (E 127)
Source: EU CosIng — Annex IV · checked Oct 16, 2026
No specific rule on file. The FDA regulates few cosmetic ingredients by name; no rule does not mean approval.
How Acid Red 51 is treated in 3 more markets, from the overseas cosmetic regulation database compiled by Korea's MFDS. Always confirm with the regulator of that country before selling there.
| Market | Status | Conditions |
|---|---|---|
| AS ASEAN (10 countries) | Prohibited | MFDS summary (Korean): when used as a substance in hair dye products^염모제로 사용되는 경우에 한함 |
| BR Brazil | Prohibited | MFDS summary (Korean): when used as a substance in hair dye products^염모제로 사용되는 경우에 한함 |
| AR Argentina | Prohibited | MFDS summary (Korean): when used as a substance in hair dye products^염모제로 사용되는 경우에 한함 |
Source: MFDS cosmetic ingredient use restrictions — overseas regulations · checked Oct 16, 2026
ACID RED 51 산성적색51호
Information only, not medical advice. Rules change — always check the linked official source. If you are pregnant, have a skin condition or allergies, ask a dermatologist or pharmacist.
In the EU's CosIng records it is listed as “Prohibited” (EU CosIng — Annex II).
We found no specific rule for it in Korea's MFDS records. That is not an approval or a safety statement.
We found no specific rule for it in the FDA's records. That is not an approval or a safety statement.
The EU's CosIng inventory lists its functions as: colorant, hair dyeing.
Korea's MFDS standard Korean name is 산성적색51호.