Key takeaway
What This Development Means
The European Chemicals Agency (ECHA) has opened a public consultation on the updated classification of 3,4-dimethyl-1H-pyrazole (3,4-DMP). The consultation focuses on reproductive toxicity, following concerns raised about the substance’s effects in relation to its analogue, 3,4-DMPP. Stakeholders are invited to submit comments by 25 September 2024. The feedback will help determine the final harmonised classification and labelling of 3,4-DMP, which is widely used in industrial applications. This consultation could significantly impact industries using the substance.
What are the primary uses of 3,4-dimethyl-1H-pyrazole?
3,4-dimethyl-1H-pyrazole (3,4-DMP) is commonly used in industrial applications, including the production of agrochemicals, pharmaceuticals, and chemical intermediates for various synthetic processes.
What are the potential risks associated with 3,4-dimethyl-1H-pyrazole?
The potential risks include acute toxicity through ingestion, inhalation, and dermal exposure, as well as reproductive toxicity and carcinogenicity. These risks are being assessed in the public consultation to ensure proper classification and labelling for safety.
Source basis: https://echa.europa.eu/harmonised-classification-and-labelling-targeted-consultations/-/substance-rev/77710/term
The European Chemicals Agency (ECHA) has launched a public consultation as part of its harmonised classification and labelling (CLH) process for 3,4-dimethyl-1H-pyrazole (3,4-DMP), a chemical substance commonly used in various industrial applications. This consultation seeks to gather further insights on the reproductive toxicity of the substance, particularly in relation to its analogue, 3,4-dimethyl-1H-pyrazol-1-ium dihydrogen phosphate (3,4-DMPP). The consultation is open until 25 September 2024.
Background On The Substance
The current classification of 3,4-DMP in Annex VI of the Classification, Labelling and Packaging (CLP) Regulation includes:
Acute Toxicity Category 4 (Oral): H302Serious Eye Damage Category 1: H318Aquatic Chronic Toxicity Category 3: H412
Belgium, the dossier submitter, has proposed expanding this classification to include additional hazards, such as Acute Dermal and Inhalation Toxicity (H312, H332), Carcinogenicity (H351), Reproductive Toxicity (H361f), and Specific Target Organ Toxicity (H373). These proposed changes aim to ensure the safe use and handling of the substance by industrial operators.
Focus Of The Current Consultation
During the RAC-70 CLH working group meeting in July 2024, experts highlighted significant similarities between 3,4-DMP and its analogue, 3,4-DMPP. Notably, reproductive toxicity studies conducted on 3,4-DMP involved relatively low doses, which may have skewed the findings. The working group expressed concerns that the absence of observed maternal toxicity in these studies could be due to insufficient exposure levels, especially considering the higher doses used in 3,4-DMPP studies, where adverse effects were reported.
This consultation invites stakeholders to comment on the proposed read-across justification between the two substances. The data collected will play a pivotal role in determining the final classification of 3,4-DMP.
How To Participate
Stakeholders, including manufacturers, downstream users, and the scientific community, are encouraged to provide comments on the reproductive toxicity data and other scientific evidence relevant to the classification of 3,4-DMP. The consultation is accessible through the ECHA’s website and closes at 23:59 Helsinki time on 25 September 2024.
Conclusion
The outcome of this consultation could have far-reaching implications for industries utilising 3,4-DMP. By participating, stakeholders can help shape the regulatory landscape, ensuring that safety measures are adequately aligned with the latest scientific data.
Related Articles

CLP Annex VI Update: EU Proposes Major Transfer Of SVHC And Hazardous Substances
The proposed CLP Annex VI update introduces harmonised classifications for over 100 hazardous substances, including SVHCs, PFAS and endocrine disruptors. The changes will impact labelling, safety data and product formulation across multiple sectors, requiring early compliance planning and supply chain engagement.

Austria Signals Endocrine Disruptor Proposal For Potassium Chlorate Under EU CLP
ECHA’s CLH intentions registry shows Austria plans a dossier for potassium chlorate, including proposed endocrine disruptor hazard classes for human health and the environment.

ECHA Publishes Provisional Draft Agenda For RAC 76 Meeting
A new provisional RAC 76 agenda gives an early view of upcoming risk assessment discussions that can shape hazard classification and compliance planning.
