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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

Sodium dichromate
EC Number
CAS Number
Entry Nr in Annex XIV
Use name
The use of sodium dichromate as in-situ corrosion inhibitor in a closed water/ammonia absorption cooling system
Broad information on use applied for (conditions of use and function)
The use of sodium dichromate as in-situ corrosion inhibitor takes place in a fully closed water/ammonia absorption cooling system. In this system, the evaporation of the ammonia creates a cold surface to cool the monomer feed of a solution polyethylene manufacturing plant. The driving force for the evaporation of the ammonia is provided by the absorption of ammonia in water. The absorption cooling system is of an industrial size and it consists of several separate pieces of equipment such as heat exchangers, piping, pumps and absorption and desorption towers.

Due to the chemistry of the ammonia-water system, corrosion of the carbon steel piping and equipment cannot be avoided without an effective inhibitor. This corrosion can happen fast and is unpredictable. Any corrosion would ultimately lead to failure of the equipment with possible resulting ammonia emissions. Sodium dichromate plays its role in this system, preventing corrosion and the potential for equipment failure. The system is a fully closed system requiring only very little intervention. The activities related to the use of sodium dichromate in this process are restricted to sampling, refilling and maintenance, which are only required once or twice per year.

Sodium dichromate does not have any contact with the monomer feed and is not present in the final products.

The functional requirements of sodium dichromate as corrosion inhibitor are as follows:

  • Ensure protection of carbon steel
  • Provide protection at high pH
  • Provide corrosion protection in water/ammonia system
  • Provide protection in liquid and in vapour phase
  • Be functional and stable at the operational pressure and temperature
  • Cause no additional fouling
  • Prevent H2 formation
  • Be soluble in water
  • Compatible with current service (use of sodium dichromate)
  • Not create oxygen in gas phase
  • Commercially available
Annual tonnage used: 0.090 tonnes/year
Review period requested: 18 years
Use applied for number in application for authorisation
Broad information on use applied for (Use descriptor system)
Sector of end use (SU): 12
Environmental release category (ERC): 7
Process category (PROC): 1, 8a, 8b, 15
Product category (PC): 0: Other: corrosion inhibitor
Technical Function: Corrosion inhibitors and anti-scaling agents
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
Borealis Plastomers B.V.
Application type
Commission decided
Other consultations on the same/ similar use
Comments submitted to date
No comments received
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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