HC RED NO. 18

What official classifications and rules say for each group. A classification describes the hazard of the pure substance, not the risk of a product that contains it, which depends on the dose and the exposure.

Prohibition or serious classificationThe text prohibits the substance for this use, or ranks it among the most serious hazards (known or presumed carcinogenic, mutagenic or reprotoxic, identified endocrine disruptor).Worth watchingThe text sets a condition or flags a hazard worth knowing: allergen, suspected effect, condition for children, hazard to the aquatic environment.For informationOfficial information with no condition on a finished product: warning to read, irritation of the pure substance.

• Pregnancy and breastfeeding

  No classification harmonised by the European Union covers reproduction, the unborn child or breastfeeding for this substance. This does not mean it has been judged to have no effect during pregnancy.

• Babies and children

  The Cosmetics Regulation sets no age-related condition for this ingredient.

• Skin, eyes and allergies

  No harmonised classification for sensitisation, irritation or eye damage, and no obligation to label it as an allergen.

• Environment

  No harmonised classification as hazardous to the aquatic environment, and it is not on ECHAEuropean Chemicals Agency.'s Candidate List as an endocrine disruptor for the environment.

• Read on the label

  For informationOfficial information with no condition on a finished product: warning to read, irritation of the pure substance.

  For information Annex III, entry 386, requires this to be printed on the pack: “For (a): To be printed on the label: The mixing ratio. “Hair colourants can cause severe allergic reactions. Read and follow instructions. This product is not intended for use on persons under the age of 16. Temporary ‘black henna’ tattoos may increase your risk of allergy. Do not colour your hair if: — you have a rash on your face or sensitive, irritated and damaged scalp, — you have ever experienced any reaction after colouring your hair, — you have experienced a reaction to a temporary ‘black henna’ tattoo in the past”.”.

Allowed with restrictions

Other conditions

For (a): After mixing under oxidative conditions the maximum concentration applied to hair must not exceed 1,5 %.

Warning to print

For (a): To be printed on the label: The mixing ratio. “Hair colourants can cause severe allergic reactions. Read and follow instructions. This product is not intended for use on persons under the age of 16. Temporary ‘black henna’ tattoos may increase your risk of allergy. Do not colour your hair if: — you have a rash on your face or sensitive, irritated and damaged scalp, — you have ever experienced any reaction after colouring your hair, — you have experienced a reaction to a temporary ‘black henna’ tattoo in the past”.

Entry

Annex III, No 386

Substance

2-chloro-4-{(E)-[3-(methylthio)-1,2,4-thiadiazol-5-yl]diazenyl}phenol

Glossary names

HC Red No 18

CAS

1444596-49-9

United Kingdom (Great Britain)

• No specific rule in the Cosmetics Regulation

Entry 386 of Annex III of EU law (Regulation (EU) 2026/909) has no equivalent in British law.

Switzerland

Regulation (EC) No 1223/2009 applies in Switzerland (Article 54 of the Ordinance on Foodstuffs and Utility Articles).

United States, federal rules

None of the integrated sections of the federal code (21 CFR 700.11 to 700.27 and 250.250) targets this name. The FDA does not publish a list of allowed ingredients.