REACH - Applications for authorisation AFA044-01 – Sodium dichromate

Closed 1 Jan 2024

Opened 6 Nov 2023


Public consultation on alternatives

 Reference: AFA044-01

Applicant: Brenntag UK Ltd

Application type: Review report

Substance name:

Sodium dichromate

      • CAS: 10588-01-9
      • EC: 234-190-3

Proposed use: Inorganic finish stripping using sodium dichromate in aerospace and defence industry and its supply chains

Broad information on use applied for (conditions of use and function):

Sodium dichromate is used in the aerospace and defence industries (comprising of the civil aviation, defence/security, and space industries, along with aeroderivative products) and its supply chains. It is a key component in surface treatment processes.

To protect, or improve the performance of, the metallic substrate, there are a number of different inorganic coatings that may be applied to the surface of a component.  Though inorganic coatings are applied for specific purposes, it is essential that the finish can also be removed. The removal of a coating or surface finish from a substrate is known as stripping. The stripping of anodised layers, conversion coatings or hard chrome plating with sodium dichromate-based solutions may be used as a surface pre-treatment step to remove the finish as part of maintenance, repair and overhaul (MRO) work or for rework, when surface finishes are non-confirming or must be removed for quality testing. The key function of the chromates in inorganic finish stripping is to ensure negligible or no effect on the underlying substrate whilst supporting the efficient removal of the inorganic finish.

The applicant has identified a shortlist of potentially suitable alternatives. However, due to complexity of design challenges, performance requirements, safety requirements and regulatory controls that must be tested for each listed alternative, and the need for industrial implementation in the whole supply chain, the applicant is seeking a review period of 12 years.

This “applied for use” involves the continued use of sodium dichromate across approximately 20 sites in Great Britain (GB).

List of descriptors: 

  • Sector of end use (SU): 0: Other- Aerospace and defence industry and its supply chain
  • Environmental release category (ERC): 6b
  • Process category (PROC): 0, 5, 8b, 9, 13, 15, 28
  • Product category (PC): 14
  • Article category related to subsequent service life ( AC):
  • Technical Function: To ensure negligible or no effect on the underlying substrate whilst supporting the efficient removal of the inorganic finish

Annual tonnage used: < 0.2 tonnes/annum

Review period requested: 12 years 

How to submit comments

Provide some basic information on possible alternative(s) in the online survey below but more detailed information should be provided in document(s) prepared using the commenting templates in the related section below. A “public version” should always be completed and will be published after the consultation has closed. If you want to include confidential information in your submission, please additionally complete a “confidential version” and submit both versions as attachments.

The consultation lasts for 8 weeks (unless otherwise specified) and closes at 23:59 London time (BST).


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