REACH – Applications for authorisation AFA002-01 – OPEO

Closed 8 Sep 2021

Opened 14 Jul 2021


Public consultation on alternatives

Reference: AFA002-01

Applicant: MeiraGTX UK II Limited

Application type: Initial

Substance name: 4-(1,1,3,3-tetramethylbutyl)phenol, ethoxylated (4-tert-OPnEO)

EC Number

CAS Number: 9036-19-5

Proposed use: Use of 4-tert-OPnEO in the development of gene therapies

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

The application is for use of the substance at a single UK site.

The applicant uses 4-tert-OPnEO as a cell lysing agent, for the extraction of proteins and organelles during the manufacture of gene therapy products. The substance is formulated into a buffer solution which is subsequently introduced to cells in culture which have been engineered to produce the gene therapy vector; when the cells are lysed the vector is released into the lysate. The lysate is then filtered and purified via successive downstream processes in order to yield the applicants product.

During purification of the product, the majority of the 4-tert-OPnEO used in the process is collected for offsite incineration as hazardous waste. A small proportion is discharged to sewer and could enter the aquatic environment.

The material outputs from the applicant’s manufacturing process that contain 4-tert-OPnEO are:

  • Chemical waste
  • Hazardous waste
  • Liquid waste
  • Samples
  • Product

List of descriptors:

  • Sector of end use (SU): 20
  • Environmental release category (ERC): ERC4
  • Process category (PROC): 3, 8b, 9 and 15
  • Product category (PC): 29
  • Article category related to subsequent service life (AC): n/a
  • Technical Function: cell lysis agent

Annual tonnage used: <100kg

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)