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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. Its decision-making process can be followed through the comitology register, where further information is published about the REACH Committee's past and upcoming meetings.

On 1 February 2020, the United Kingdom (UK) withdrew from the EU. The transition period provided by the withdrawal agreement ended on 31 December 2020. As of 1 January 2021, an application for an authorisation submitted by a person established in the UK (except Northern Ireland) is no longer valid in the EU, unless that application has been transferred to a legal entity established in the EU or Northern Ireland before the end of the transition period. Therefore, authorisation applications and decisions in so far as these concern persons established in the UK (except Northern Ireland) are no longer considered valid. The table below will be updated at a later stage.


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Substance Details

4-(1,1,3,3-tetramethylbutyl)phenol, ethoxylated
EC Number
CAS Number
Entry Nr in Annex XIV
Use name
Mixing, by Aerospace and Defence Companies, and their associated supply chains, including the Applicants, of base polysulfide sealant components with OPE-containing hardener, resulting in mixtures containing < 0.1% w/w of OPE for Aerospace and Defence uses that are exempt from authorisation under REACH Art. 56(6)(a).
Broad information on use applied for (conditions of use and function)
This use covers on site mixing of the OPE-containing hardener with the base of the polysulfide sealants. The use covers mixing of two compartment kits (either mechanically, pneumatically, or manually), mixing in small scale batches by hand from can kits, as well as bulk mixing by machine from drum kits.
Polysulfide sealants, containing very low concentrations of OPE, are used to deliver specific safety functions in production, maintenance and repair within the aerospace and defence industry, in accordance with the requirements of airworthiness regulations or applicable defence and space requirements. Their uses include but are not limited to:
- Sealing structures/components to
a. keep moisture or other fluids out (to prevent corrosion or attack of structures/components)
b. keep fluids in (e.g. fuel, hydraulic fluids, etc.)
c. prevent airflow to maintain cabin pressure, and
d. to seal defence systems against chemical agents
- Isolating components to separate dissimilar metals/surfaces to prevent corrosion or provide thermal/electrical insulation
- Filling gaps to create an aerodynamic surface (aero faring / aero smoothing) and eliminate moisture accumulation or traps
- Provide adhesion in engines and nacelles, where flexibility at extreme temperatures and compatibility with mating gap filler is required; bonding structures requiring flexibility; and bonding/sealing of wires
- Electrical potting in connectors, circuit boards, etc.

They are used in a range of applications including fuel tanks (to prevent leakage), window sealing (ensuring air tightness and pressurization of passenger cabins), actuators, electronic controller connections, gyros, wiper blade systems, propeller blades, ball screws for actuators, flight control rudder pedals, joint sealing of general A&D product structures during assembly process, to assemble structures, etc. They can also fulfil some adhesive and A&D product coating functions.
The unique properties of this category of sealants that make it suitable in key A&D applications include, but are not limited to:
- Resistance to degradation by fuel and other chemicals
- Flexibility over a wide range of temperatures, most uniquely extreme cold
- Adhesion to a wide range of substrates
- Ability to stress-relax, thereby maintaining adhesion to expanding and contracting substrates
- Compatibility with a wide range of paint and primer systems

Polysulfide sealants in the scope of this application for authorisation comprise a base and a hardener component. Only the hardener component contains low concentrations (up to 0.5%) of OPE. This use covers the mixing of the base and the hardener components. Once mixed, the concentration of OPE in the sealant is always less than 0.1% w/w, so the mixed sealant is exempt from authorisation.

The Applicants state that there is no release of hardener or sealant to wastewater from the facility during sealant mixing and related cleaning and maintenance activities. OPE contaminated waste generated during mixing is managed as hazardous by licensed third party waste management contractors. The waste is processed in line with the applicable local, regional, and national regulations. Compliance with these regulations precludes release to the environment and generally involves incineration.

Annual tonnage used: <1 tonne
Number of sites: >100
Review period requested: 4 years
Use applied for number in application for authorisation
Broad information on use applied for (Use descriptor system)
Sector of end use (SU): 0: other: Aerospace and Defence
Environmental release category (ERC): 6b
Process category (PROC): N/A
Product category (PC): 1
Article category related to subsequent service life (AC): N/A
Technical Function: The presence of OPE in the hardener results from Use 1. OPE has no known independent function during Use 2; however, testing is still ongoing to verify that OPE does not have any technical function, and its removal has no negative impact on its use in manufacturing or in article performance.
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
PPG Europe B.V. in its legal capacity as Only Representative of PRC DeSoto International Inc. – OR5; Sealants Europe SAS; PPG Industries (UK) Ltd.; Boeing Distribution, Inc. – [Decision discontinued as of 01/01/2021]; Aviall UK Inc.; Wesco Aircraft EMEA Ltd (Poland); HAAS GROUP INTERNATIONAL SP. Z.O.O [application transferred from: “Wesco Aircraft EMEA, LTD (UK)” due to a notified legal entity change]
Application type
Opinions adopted
Other consultations on the same/ similar use
Comments submitted to date
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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