Substitution warning

The substitution of harmful chemicals is an important part of the Harmonised Mandatory Control Scheme (HMCS).  The UK is obliged to implement the policy to replace chemical substances identified as candidates for substitution. Products containing substitutable chemical substances are identified by the presence of a substitution warning placed on the product template.

An offshore chemical will be flagged with a substitution warning if:

• The chemical is listed in Annex 2 of the OSPAR Strategy with regard to Hazardous Substances; or
• The chemical is inorganic and has a LC50 or EC50 < 1 mg l^-1; or
• The chemical has a biodegradation result < 20% during 28 days; or
• The chemical meets two out of the following three criteria (organic substances only):
• • Biodegradation in 28 days < 70% (OECD 301A, 301E) or < 60% (OECD 301B, 301C, 301F, 306);
  • Bioaccumulation (log Pow) > 3 and molecular weight of the substance is < 600, or, BCF > 100
  • Toxicity LC50 or EC50 < 10mg/l.

A reliable value of Log Pow cannot be calculated for surfactants and therefore cannot be used to indicate whether a surfactant might bioaccumulate. OSPAR requires Regulatory Authorities to take a precautionary approach where data are ambiguous or missing. So substitution warnings will be applied to those surfactants that have a molecular weight of <600 and are either <60% or 70% biodegradable in 28 days (according to the test protocol) or have an EC50 or LC50 <10 mg l-1, unless Cefas is satisfied that other evidence submitted by the supplier indicates that the substance should not bioaccumulate.

• Assessing Bioaccumulation of Surfactants (PDF, 74 KB)

During the risk assessment process operators are required to consider the selection of products both in terms of the magnitude of their Risk Quotient (RQ) and the presence of hazardous substances including candidates for substitution. Operators are required to provide a robust defence for the continued use of products that have a high RQ or contain candidates for substitution.

Chemical suppliers must consider the advice they provide to operators that justifies continued use of any product containing candidates for substitution. In addition suppliers should consider a managed approach to the replacement of any undesirable components, leading to the reformulation and re-certification of products.

Cefas are happy to explain any substitution warning assigned to a product, and to discuss any approach you may be considering in addressing these issues, OCNS Contacts.

It should also be noted that operators will be encouraged to select products that do not have a substitution warning and therefore a supplier may wish to seek alternatives at the product development stage. However, there may be good technical reasons why a particular substance cannot immediately be substituted. The supplier will wish to highlight these to operators so that they can include this information in their justification for continued use of the product.

Further detail on the Cefas approach to applying substitution warnings can be found in within the downloadable document Cefas approach to applying substitution warnings (PDF, 101 KB)

Substitution FAQs

1. My product has a substitution warning applied to it. What does this mean and what action should I take? 
2. Why are warnings assigned to the whole product, when the component to which the warning applies is only a small fraction of the total composition? 
3. My product carries a substitution warning, yet none of my company's data on the components appear to justify the warning?
4. My product is likely to attract a substitution warning on account of a poor result in an OECD 306 biodegradation test. What should I do?
5. What has happened to the taint warning formerly displayed on a template?
6. Are physicochemical or toxicity data that are calculated using Quantitative Structure Activity Relationships (QSAR) acceptable for substance registration?