DIMETHYLOL ETHYLENE THIOUREA (1,3-bis(hydroxymethyl)-2-imidazolidinethione)
Official label name (INCIInternational name of cosmetic ingredients: the one printed on the pack. name, EU glossary of cosmetic ingredient names), No 9039
- Allowed with restrictions (Annex III)
DIMETHYLOL ETHYLENE THIOUREA (1,3-bis(hydroxymethyl)-2-imidazolidinethione): Allowed with restrictions, with limits depending on the product type (Annex III, entry 44), under Regulation (EC) No 1223/2009. Annexes of the Regulation consulted on 23 October 2026.
Who it concerns
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 44, requires this to be printed on the pack: “Contains Dimethylol ethylene thiourea”.
CosIng, Annex III of Regulation (EC) No 1223/2009 (restricted substances), retrieved 23 October 2026, source updated 13 October 2026.
In plain words
What it is used for
Functions declared by manufacturers:
Antimicrobial: helps control the growth of micro-organisms on the skin.
Hair conditioning: leaves the hair easy to comb, supple, soft and shiny and/or imparts volume, lightness, gloss, etc.
Functions declared in the CosIngThe European Commission's database of cosmetic ingredients. inventory. CosIng, inventory of cosmetic ingredients (INCI names, CAS, EC, functions), retrieved 21 October 2026.
Definitions of functions (decision repealed on 8 May 2020, cited for information). Decision 2006/257/EC, inventory of cosmetic ingredients (definitions of functions), retrieved 22 October 2026.
What the rules say
Allowed, with restrictions: Annex III sets a maximum concentration, the product types allowed and a warning to be printed on the packaging. Ingredient lists do not give quantities, so the concentration cannot be checked on the label; the warning can.
CosIng, Annex III of Regulation (EC) No 1223/2009 (restricted substances), retrieved 23 October 2026, source updated 13 October 2026.
Origin and odour
No natural occurrence recorded in Wikidata (LOTUS database); this does not prove that the ingredient is synthetic.
Basis: one CosIng CAS, with no natural occurrence recorded in this database.
Wikidata: names of substances in six languages and taxa in which they occur (largely from the LOTUS database), retrieved 23 October 2026.
Other names: 1,3-bis(hydroxymethyl)-2-imidazolidinethione (English).
Wikidata: names of substances in six languages and taxa in which they occur (largely from the LOTUS database), retrieved 23 October 2026.
Present in 0.0% of recorded cosmetics (0 out of 22 705).
Open Beauty Facts, export of cosmetic products, retrieved 23 October 2026.
Data “Open Beauty Facts and its contributors”, licensed under ODbL 1.0 (opendatacommons.org/licenses/odbl/1-0); derived table distributed under the same licence.
The text of the annexes
Allowed with restrictions
| Product type | Other conditions |
|---|---|
| (a) Hair products | Not to be used in aerosol dispensers (sprays) |
| (b) Nail products | pH < 4 |
- Maximum concentration
- 2%
- Warning to print
- Contains Dimethylol ethylene thiourea
- Entry
- Annex III, No 44
- Substance
- 1,3-Bis(hydroxymethyl)imidazolidine-2-thione
- Glossary names
- DIMETHYLOL ETHYLENE THIOUREA
- CAS
- 15534-95-9
- EC
- 239-579-1
Regulation (EC) No 1223/2009, Annex III, entry 44. CosIng, Annex III of Regulation (EC) No 1223/2009 (restricted substances), retrieved 23 October 2026, source updated 13 October 2026.
Entry from Regulation (EC) No 1223/2009, adopted on 30 November 2009.
What has changed, and what will change
Dates of the texts that cover this ingredient. A text date may cover several substances: the details of each entry are below.
Annex III, entry 44: introduced or replaced by Regulation (EC) No 1223/2009
Annex III, entry 44: applies from this date
Identity
- CosIng identifier
- 33502
- CAS (according to CosIng)
- 15534-95-9
- EC (according to CosIng)
- 239-579-1
- Declared functions
- Antimicrobial, Hair conditioning
- Wikidata
- Q27279399
- PubChem
- 27369
- ECHA InfoCard
- 100.035.966
- InChIKey
- QXYJLKUVMPXXKA-UHFFFAOYSA-N
CosIng inventory. CosIng, inventory of cosmetic ingredients (INCI names, CAS, EC, functions), retrieved 21 October 2026.
Wikidata, items with a CosIng identifier (P3073), retrieved 22 October 2026.
Wikidata, PubChem and ECHA links are published only when verified: same CosIng identifier, a single item, matching CAS number.
Elsewhere in the world
Information on other jurisdictions, with no effect on sale in France. What is covered, and what is not yet.
Comparison between countries
Most restrictive status in each country, and the maximum concentration cited. The details and the source of each rule follow.
| Country | Rule | Maximum concentration cited |
|---|---|---|
| European Union | Allowed with restrictions | 2% |
| United Kingdom | Allowed with restrictions | 2% |
| Switzerland | EU Regulation applies | 2% |
| United States (federal) | No federal rule recorded | not cited |
| Canada | No entry in the lists recorded | not cited |
| Japan | No entry in the lists recorded | not cited |
| South Korea | Restricted | 2% |
| China | Not on the prohibited lists recorded (lists of allowed substances are not recorded) | not cited |
| Australia | No entry in the lists recorded | not cited |
| ASEAN | Restricted (conditions or maximum concentration) | 2% |
| Taiwan | No entry in the lists recorded | not cited |
| Brazil | No entry in the lists recorded | not cited |
United Kingdom (Great Britain)
- Allowed with restrictions (Annex III)
Same entries as in the European Union. Their maximum concentrations are compared in the “Comparison between countries” table; other conditions (product types, warnings) may differ.
Annexes II to VI in force. United Kingdom, Annexes II to VI of Regulation (EC) No 1223/2009 as retained and amended, retrieved 21 October 2026.
Contains public sector information licensed under the Open Government Licence v3.0.
Northern Ireland applies EU law.
Switzerland
Regulation (EC) No 1223/2009 applies in Switzerland (Article 54 of the Ordinance on Foodstuffs and Utility Articles).
Switzerland, FDHA Ordinance on Cosmetic Products (OCos, SR 817.023.31), consolidated version, retrieved 22 October 2026.
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.
United States, 21 CFR part 700 and section 250.250 (FDA rules on cosmetic ingredients), eCFR, retrieved 21 October 2026.
The eCFR is not an official legal edition of the Code of Federal Regulations.
South Korea
- Restricted: 1,3-비스(하이드록시메칠)이미다졸리딘-2-치온 (DIMETHYLOL ETHYLENE THIOUREA)
별표 2, 기타 (other substances with limits), entry 34, page 33. Limit: 두발용 제품류 및 손발톱용 제품류에 2% (다만,에어로졸(스프 레이에 한함) 제품에는 사용금지).
Conditions, source text, in Korean
비고: 기타 제품에는 사용금지
South Korea, MFDS Regulation on Safety Standards for Cosmetics, Notification 2026-19, retrieved 22 October 2026.
Source: 식품의약품안전처 (MFDS), 화장품 안전기준 등에 관한 규정, via law.go.kr; table formatted by the publisher of this site.
ASEAN (South-East Asia)
- Restricted (conditions or maximum concentration): 1, 3-Bis (hydroxymethyl) imidazolidine-2-thione Dimethylol ethylene thiourea
Annex III (restricted substances), entry 44, page 129. Limit: (a) 2% (b) 2%.
Conditions, source text
Field of application and/or use: (a) Hair care products (b) Nail care products | Other limitations and requirements: (a) Prohibited in aerosol dispensers (sprays) (b) The pH of the product as applied must be less than 4 | Conditions of use and warning which must be printed on the labels: Contains 1, 3-Bis (hydroxymethyl) imidazolidine-2-hione
ASEAN Cosmetic Directive, Annexes II, III, IV, VI and VII (version 2026-1 of 22 June 2026, Annex VII 2025-2), retrieved 24 October 2026.
Source: ASEAN Cosmetic Documents, Annexes of the ASEAN Cosmetic Directive, as published by the Health Sciences Authority (HSA, Singapore); table extracted and formatted by the publisher of this site, with no endorsement by HSA or ASEAN.
Glossary: Commission Implementing Decision (EU) 2025/1175. Page updated on 23 October 2026.