REACH - Applications for authorisation AFA045-02 Chromium trioxide

Closed 7 Aug 2023

Opened 12 Jun 2023


Public consultation on alternatives

Reference: AFA045-02

Applicant: Indestructible Paint Ltd

Application type: Initial

Substance name: Chromium trioxide

  • EC No: 215-607-8
  • CAS No: 1333-82-0

Proposed use: Use of chromium trioxide containing products as part of slurry coating applications for the protection of ferrous alloys in industrial gas turbine and related equipment for non-aerospace and aeroderivative applications.

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

Slurry coating is a surface treatment where typically steel components and nickel or cobalt-based alloys are coated with a slurry paint containing chromium trioxide and afterwards are cured at high temperatures. Slurry coating provides corrosion resistance, chemical resistance, high temperature oxidation resistance, adhesion to components which produce a smooth finish and enhance the technical performance of turbines.

Applied for use at <= 22 applicator or maintenance, repair and overhaul (MRO) sites in GB for use in the following primary sectors:

  • The power generation industry – enabling the longevity of machinery (gas turbine engines) and providing enhanced efficiency due to the smooth surfaces created
  • Oil and gas industry – to provide protection of offshore turbines in challenging environments
  • Manufacturing sectors – enabling sites to benefit from power generation and in some cases the combination of power generation and heat
  • Non-manufacturing sectors – where industrial gas turbines are used for power generation and/or heat, including hospitals, utilities, landfill and incineration, district heating
  • Back-up power generation – enabling the longevity of turbines that may need to be activated in emergency situations (including hospitals and airports)

Efforts to identify an alternative have been ongoing in the industry for several years. Following initial screening tests, alternative candidate coatings, both Metallic Ceramic Aluminium Coatings (MCAC) and diffusion coatings, have been identified and are currently undergoing further development.

List of descriptors: 

  • Sector of end use (SU): 17
  • Environmental release category (ERC): 5
  • Process Category (PROC): 0, 5, 7, 8a, 8b, 9, 10, 28
  • Product category (PC): 14
  • Article category related to subsequent service life (AC): N/A
  • Technical Function: Other: high temperature oxidation resistance (dry heat resistance); cyclic heat-corrosion resistance; adhesion to substrate; chemical resistance (hydraulic fluids, engine oils, fuel); smooth surface finish

Annual tonnage used:

  • 0.1 - 1 tonnes/year

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).


  • Applications for authorisation


  • Registration, Evaluation, Authorisation & restriction of CHemicals (REACH)