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Adopted opinions and previous consultations on applications for authorisation

Adopted opinions and previous consultations on applications for authorisation


This page provides further information on the applications for authorisation or review reports, which have undergone consultation. The applications for authorisation are in the opinion development phase until the final opinions of the Committees for Risk Assessment and Socio-economic Analysis have been adopted and sent to the European Commission. The European Commission's decision-making process can be followed through the comitology register, where further information is published about the REACH Committee's past and upcoming meetings.

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Substance Details

Chromium trioxide
EC Number
CAS Number
Entry Nr in Annex XIV
Use name
Industrial use of a chromium trioxide based surface treatment mixture applied on safety-critical rotating components of commercial and military aircraft engines, whose failure endangers airworthiness
Broad information on use applied for (conditions of use and function)
The applicant uses chromium trioxide as part of a paint coating mixture that is applied by spraying and brush application processes on safety-critical components of the engines that the company manufactures or repairs in order to prevent corrosion damage and maintain the performances of shafts and other critical parts of engines. This use takes place at 4 sites located in the EU.

Chromium trioxide is a component of a liquid mixture, “slurry” which can be sprayed onto a surface to form a coating, similar to paint. The paint coating, also called “metallic-ceramic coatings”, is deposited onto a surface using air-atomized spray guns, which are commonly used to deposit conventional paints, or, sporadically applied for touch-up paint activity by brushing. The coating is then cured at a high temperature close to 340 °C. This process is carried out by 12 workers (including 3 workers with a sporadic brush application activity). The paint coating containing chromium trioxide is provided already formulated from the USA.

Chromium trioxide is used within the SermeTel W mixture in order to provide a unique combination of seven functional requirements:

  • stabilization of aluminium
  • cohesion of aluminium
  • cohesion binder
  • adhesion promoter
  • surface passivation
  • corrosion inhibitor
  • high temperature resistance
Consequently, the coating mixture provides an effective physical coat protection against corrosion attack and also creates an additional anti-corrosive sacrificial protection thanks to the combination of chromium trioxide with aluminium substance. Substituting this paint coating on safety-critical components already certified requires a “Major change approval” validation that must guarantee the compliance with characteristics needed to address the airworthiness requirements: endurance test on ground; fan blades retention; fire resistance; fluid compatibility; compatibility with manufacturing method; corrosion resistance; integration capability and adequate interface.

In order to prove the above mentioned airworthiness characteristics fulfilment, a potential alternative needs to pass the following validation steps to validate both technical and process aspects, i.e: laboratory tests, ground endurance engine tests and complete a “Major change approval” validation. Considering the high-safety critical components concerned by Use-1 and the simultaneous ramp-up of the new LEAP engine, the Applicant needs to implement in-flight testing to ensure the sustainability of the performances of the potential alternative under actual flight conditions, prior to the launch of the industrialisation phase of the components with a new substitution process/product.

Additional information on the process and on the substitution requirements can be found in the AoA-SEA respectively on pages 31-35 and 76-82, as well in the CSR on pages 27-33.

Annual tonnage used: 60 kg
Review period requested: 10 years
Use applied for number in application for authorisation
Broad information on use applied for (Use descriptor system)
Sector of end use (SU): 3, 17, 22
Environmental release category (ERC): 5
Process category (PROC): 7, 8b, 10, 21, 22, 26
Product category (PC): 14
Technical Function: The main properties: corrosion inhibitor, high temperature resistance, adhesion promoter, surface passivation.
Summary table of RMMs and OCs (non confidential)
Section 9 and 10 of the CSR (original and updated, if available) (non confidential)
Analysis of Alternatives (non confidential report)
Substitution Plan (non confidential summary)
Socio-Economic Analysis (non confidential report)
Joint Analysis of Alternatives and Socio-Economic Analysis (non confidential report)
Explanatory note
Additional information
Safran Aircraft Engines [name of applicant in the original application: SNECMA updated due to a notified change of corporate name]
Application type
Commission decided
Other consultations on the same/ similar use
Comments submitted to date
Download Comment [ZIP]
Response to comments by applicant
Responses to RAC and SEAC requests by Applicant(s) (non confidential)
Compiled RAC and SEAC opinions
Minority positions
Adopted commission decision (OJ summary)
Authorisation decision

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