Public consultation on the expert appraisal work on the consideration of chemical mixtures for the setting of reference values : review of existing methods and recommendations

Taking into account human exposure to mixtures and the associated potential health risk is a methodological challenge for ANSES, particularly in the context of its ongoing expert missions to develop reference values. These values are useful, on the one hand, for the assessment of health risks, and, on the other hand, for public authorities who set regulatory concentrations of chemical substances that should not be exceeded to protect the health of populations (general, workers). Until now, it has only proposed values for an individual substance without taking into account the complexity of population exposures.

Anses is holding an open consultation on a draft “Existing knowledge on methods for taking mixtures into account in the areas of health risk assessment and the setting of reference values - Reflection on the setting of reference values”.

This document is a report reviewing the existing methods for taking into account mixtures in the field of human health risk assessment and the setting of reference values for chemicals (Report 1). This report is issuing recommendations on how to select contaminants, and which method to use for setting reference values for a mixture.

This work is the first stage of a work initiated in 2016 and followed by a case study applying the recommendations from the Report 1 for the development of indoor air quality guideline values (IAQGs). In the context of this expert appraisal work on IAQGs, the issue of mixtures was raised for several substances such as acrolein, acetaldehyde and formaldehyde whose exposure are often simultaneous. Aldehydes, due to their structural similarities, have similar toxicodynamic behavior in the respiratory tract which is also known to be their main organ target; their combined effects are potentially additive or even synergistic.  

A second report (Report 2), only available in French, describes this case study. This report is structured on the basis of the recommendations from the first report and tests the applicability of existing models for a mixture of aldehydes extended to other irritants in indoor air. The result of this case study is an approach to take into account the irritant effects of a mixture of substances frequently encountered in indoor air for short-term exposure. This approach is based on the determination of relative potency factors (RPF) associated with a reference compound. It is not an IAQG value as defined by ANSES, the objective not being to provide a defined value for a precise mixture of substances.

More broadly, the lessons learned from this application should contribute to the development of a methodology for taking into account mixtures in Anses’s future assessments, particularly in the context of updating the methodological guide for the setting of reference values.

Objectives of the consultation

The objectives of this public consultation phase are to allow interested parties to comment on the scientific data identified and used for this expert appraisal work, to express their views on the interpretation and implementation these data to meet the objectives set, before the publication of the Anses’ finalised reports and opinion.

This will enable ANSES to :

  • identify any important scientific publications or data that have not been taken into account ; 
  • collect any comments on the interpretation of the available data that have been made;
  • collect any information that might help improve and develop the methodology used by Anses for establishing reference values taking into account mixtures.

Public consultations submission instructions

The interested parties must use only the email address specifically created for this public consultation: consultation-publique.vgaimelange@anses.fr.

Comments or documents sent by the postal service will not be accepted.

The public consultation is open of 4 June until 19 September 2021.

Please identify yourself at the beginning of your message (last name, first name and position / job title) as well as the organization you are representing for this consultation submission if you are not submitting data in a personal capacity.

Please clearly identify the page numbers and line numbers concerned by the comments and remarks.

Comments and remarks will not be taken into consideration if : 

  • they are submitted after the deadline set for the consultation period; 
  • they do not refer to the content of the documents subject to consultation; 
  • they involve political or risk management issues, which fall outside of the filed of this work; 
  • they contain complaints against institutions, personal accusations, irrelevant or offensive declarations.

What will the data be used for ? 

At the end of the consultation period, the responses obtained will be analysed by the Agency and, depending on the scientific evidence and arguments provided, will be submitted for discussion in the expert committees ( CES ) “Risk assessments related to air environments ”and “Health Reference Values”.   

It should be noted that in the context of this expert appraisal work: 

  • the data that will be made known to the agency via the consultation phase will not be subject to a request of confidentiality; 
  • an appendix to the final report will list all respondents to the consultation; 
  • an appendix listing all changes made to the draft report following the consultation will be included in the final report.

The publication of the finalised documents will trace the evolution of the document, allowing each participant to see whether their comments and / or remarks have been taken into account. In this context, no individual response will be given to respondents.