On the 8th of April 2015, the Japanese Ministry of Health, Labour and Welfare (MHLW) officially released an amendment to the existing “Act on Control of Household Products Containing Harmful Substances”. Azo colorants are considered as harmful substances in this amendment, and can not used in household products. The amended will take effective on Apr.1, 2016.
The new amendment restricts azo colorants that can break down to release any of the 24 carcinogenic aromatic amines (Table 1) with a threshold limit of less than 30mg/kg.
Table 1: 24 carcinogenic aromatic amines
| No. | Name | CAS No. | No. | Name | CAS No. |
| 1 | 4-aminobiphenyl | 92-67-1 | 13 | 3,3’-dimethyl-4,4’-diaminobiphenylmethane | 838-88-0 |
| 2 | benzidine | 92-87-5 | 14 | p-cresidine | 120-71-8 |
| 3 | 4-chloro-o-toluidine | 95-69-2 | 15 | 4,4’-methylene-bis-(2-chloroaniline) | 101-14-4 |
| 4 | 2-naphthylamine | 91-59-8 | 16 | 4,4’-oxydianiline | 101-80-4 |
| 5 | o-aminoazotoluene | 97-56-3 | 17 | 4,4’-thiodianiline | 139-65-1 |
| 6 | 5-nitro-o-toluidine | 99-55-8 | 18 | o-touidine | 95-53-4 |
| 7 | p-chloroaniline | 106-47-8 | 19 | 2,4-toluylendiamine | 95-80-7 |
| 8 | 2,4-diaminoanisole | 615-05-4 | 20 | 2,4,5-trimethylaniline | 137-17-7 |
| 9 | 4,4’-diaminobiphenymethane | 101-77-9 | 21 | o-anisidine | 90-04-4 |
| 10 | 3,3’-dichlorobenzidine | 91-94-1 | 22 | 4-aminoazobenzene | 60-09-3 |
| 11 | 3,3’-dimethoxybenzidine | 119-90-4 | 23 | 2,4-xylidine | 95-68-1 |
| 12 | 3,3’-dimethylbenzidine | 119-93-7 | 24 | 2,6-xylidine | 87-62-7 |
Recommended test methods are:
JIS L 1940-1: 2014 Textiles – Methods for determination of certain aromatic amines derived from azo colorants – Part 1: Detection of the use of certain azo colorants accessible with and without extracting the fibres
JIS L 1940-3: 2014 Textiles – Methods for determination of certain aromatic amines derived from azo colorants – Part 3: Detection of the use of certain azo colorants, which may release 4-aminoazobenzene
This amendment restricts 24 aromatic amines which is the same as Chinese standard GB 18401-2010 National General Safety Technical Code for Textile Products, while only 22 aromatic amines are restricted in REACH Annex XVII.
CTI Suggestion
The new restriction of azo colorants in Japan has expanded the region which restricts the use of azo. Manufacturers should avoid using azo colorants in order to comply with global regulation.