Registration Dossier

Diss Factsheets

Classification & Labelling & PBT assessment

PBT assessment

Currently viewing:

Administrative data

PBT assessment: overall result

Type of composition:
boundary composition of the substance
State / form:
other: solid crystalline
Reference substance:
PBT status:
the substance is not PBT / vPvB

Classification of 2,3 -xylenol for effects in the environment:


The chemical 2,3-xylenol (CAS no. 526-75-0) is used for chemical synthesis as well as a laboratory reagent. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 2,3-xylenol. The PBT criterion was herein assessed based on experimental data in conjunction with standardized environmental fate models. Here follows a description of the PBT assessment.


Persistence assessment

The tested substance does not fulfil the P criterion within Annex XIII based on the assessment that here follows:


Biotic degradation

Various experimental studies for the target compound 2,3-Dimethylphenol (CAS No. 526 -75 -0) were reviewed for ready biodegradability property. On the basis of results for target chemical 2,3-Dimethylphenol (from peer reviewed journal, authoritative database and secondary source), it can be concluded that the test substance 2,3-Dimethylphenol was considered to be readily biodegradable in water and thus likely to be not persistent (P) in nature..


Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e. estimated to 74.1%).In soil, 2, 3-xylenol was expected to have moderate to slow mobility based upon a Log KOC value of 1.759 ± 0.001 at 25°C to 2.79, respectively. The half-life in soil (30 days estimated by EPI suite) indicates that the chemical is not persistent in soil and the exposure risk to soil dwelling animals is moderate to low.


If released in to the environment, 25.1 % of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). However, the half-life (15 days estimated by EPI suite) indicates that the exposure risk to aquatic animals is moderate to low.


Moreover, its persistent characteristic is only observed in the sediment compartment but Fugacity modelling shows that sediment is not an important environmental fate (less than 1% when estimated by EPI Suite version 4.1).


Hence it has been concluded that 2, 3-xylenol is not persistent in nature  


Bioaccumulation assessment

The tested substance does not fulfil the B criterion within Annex XIII based on the assessment that here follows:


The estimated BCF value from various databases was determined to be in the range 20 to 57, respectively and the experimental octanol water partition coefficient of the test chemical was determined to be 2.115 ± 0.002 at 25°C as per OECD TG 117 which is less than the threshold of 4.5. If this chemical is released into the aquatic environment, there should be a low risk for the chemical to bioaccumulate in fish and food chains.


Toxicity assessment

The tested substance does not fulfil the T criterion within Annex XIII based on the assessment that here follows:



The tested chemical is regarded to be not classified for carcinogenicity, mutagenicity and reprotoxicity, Further, there is no evidence of chronic toxicity, as identified by the classifications STOT (repeated exposure), category 1(oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume) or category 2 (oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume).


Aquatic organisms

All of the available short-term eco-toxicity data for fish, invertebrates and algae for the substance indicates the LC50/EC50 value to be in the range 2.72 to 92.3 mg/L. These value suggest that the substance is likely to be hazardous to Aquatic organisms at environmentally relevant concentrations and hence, considered to be classified in Aquatic Chronic category 2 as per the CLP regulation.


There are no available long-term toxicity evaluations for 2,3-xylenol. By speculation, long-term NOEC for aquatic organisms were not expected for the substance at concentration below 0.01 mg/L based on the data mentioned above.


The chemical was therefore not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII.



Based on critical, independent and collective evaluation of information summarized herein, the tested compound does not fulfil the P, B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.