2,3-xylenol

Endpoint summary

Description of key information

Acute toxicity: Oral

LD50 was estimated to be 790 mg/kg bw when rat were orally exposed with 2,3-dimethylphenol.

Acute toxicity: Inhalation

LD50 was considered to be > 85.5 mg/m³when Fischer 344 male rat were exposed to saturated vapors of 2,3-dimethylphenol for 4 h.

Acute toxicity: dermal

LD50 was estimated to be 987 mg/kg bw when Vienna White male and female rabbit were dermally exposed with 2,3-dimethylphenol.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

790 mg/kg bw

Quality of whole database:

Data is from Registry of Toxic Effects of Chemical Substances (RTECS) Database

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

85.5 mg/m³ air

Quality of whole database:

Data is from NTRL report

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

987 mg/kg bw

Quality of whole database:

Data is Klinisch 2 and from OECD QSAR toolbox

Additional information

Acute oral toxicity:

In different studies, 2,3-dimethylphenol has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments and estimated data in rodents, i.e. most commonly in mice and rats for 2,3-dimethylphenol. The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies.

In a prediction done by SSS (2017) using the Danish (Q)SAR with log kow as the primary descriptor, the acute oral toxicity was estimated for 2,3-dimethylphenol. The LD50 was estimated to be 790 mg/kg bw when rat were orally exposed with 2,3-dimethylphenol.

In another prediction done by SSS (2017) using the Danish (Q)SAR with log kow as the primary descriptor, the acute oral toxicity was estimated for 2,3-dimethylphenol. The LD50 was estimated to be 660 mg/kg bw when mice were orally exposed with 2,3-dimethylphenol.

Also further supported experimental study given by RTECS (Registry of Toxic Effects of Chemical Substances, 2016), rat were treated with 2,3-dimethylphenol orally. 50 % mortality were observed in treated rat at 562 mg/kg bw. Therefore, LD50 was considered to be 562 mg/kg bw when rats were treated with 2,3-dimethylphenol orally.

This further supported by experimental study given by RTECS (Registry of Toxic Effects of Chemical Substances, 2016), Mice were treated with 2,3-dimethylphenol orally. 50 % mortality were observed in treated mice at 302 mg/kg bw. Therefore, LD50 was considered to be 302 mg/kg bw when mice were treated with 2,3-dimethylphenol orally.

Further supported by study summarized by European Food Safety Authority (EFSA) (EFSA Journal 2011; 9(5):1990), rat were treated with 2,3-dimethylphenol in the concentration of 5000 mg/kg bw. 50 % mortality was observed in treated rat at 5000 mg/kg bw. Therefore, LD50 was considered to be < 5000 mg/kg bw when rat were treated with 2,3-dimethylphenol orally.

Thus, based on the above studies and predictions on 2,3-dimethylphenol, it can be concluded that LD50 value is less than 2000 mg/kg bw. Thus comparing this value with the criteria of CLP regulation, 2,3-dimethylphenol can be classified under “Category IV” for acute oral toxicity.

Acute inhalation toxicity:

In a study, 2,3-dimethylphenol has been investigated for acute inhalation toxicity to a greater or lesser extent. Study based on in vivo experiments in rodents, i.e. most commonly in rats for 2,3-dimethylphenol.

In a experimental study conducted by Kinkeadet al(National Technical Information Service. AAMRL-TR-87-021, APRIL 1987), Fischer 344 male rat were exposed to saturated vapors of 2,3-dimethylphenol for 4 h in a clear, 120-L ptexiglas chamber. No mortality was observed in treated male rat at 85.5 mg/m³. No effect on body weight gain and no gross lesions were observed in treated rats as compared to control. Therefore, LD50 was considered to be > 85.5 mg/m³when Fischer 344 male rat were exposed to saturated vapors of 2,3-dimethylphenol for 4 h.

Thus, based on the above studies and predictions on 2,3-dimethylphenol, it can be concluded that LD50 value is less than 20 mg/L. Thus, comparing this value with the criteria of CLP regulation, 2,3-dimethylphenol can be Not classified as acute inhalation toxicity.

Acute dermal toxicity:

In different studies, 2,3-dimethylphenol has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments and estimated data in rodents, i.e. most commonly in rats for 2,3-dimethylphenol along with the study available on structurally similar read across substance p-Cresol (CAS no 106-44-5) and o-Cresol (CAS 95-48-7). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies.

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 2,3-dimethylphenol. The LD50 was estimated to be 987 mg/kg bw when Vienna White male and female rabbit were dermally exposed with 2,3-dimethylphenol.

In another experimental study given by RTECS (Registry of Toxic Effects of Chemical Substances, 2016), mice were treated with 2,3-dimethylphenol dermally. 50 % mortality were observed in treated mice at 920 mg/kg bw. Therefore, LD50 was considered to be 920 mg/kg bw when mice were treated with 2,3-dimethylphenol dermally.

Also further supported by experimental study given by RTECS (Registry of Toxic Effects of Chemical Substances, 2016), rabbits were treated with 2,3-dimethylphenol dermally. 50 % mortality were observed in treated rabbits at 1040 mg/kg bw. Therefore, LD50 was considered to be 1040 mg/kg bw when rabbits were treated with 2,3-dimethylphenol dermally.

This is further supported by experimental study summarize by Cosmetics Ingredient Expert Review Panel (International Journal of Toxicology; Volume: 25 issue: 1_suppl, page(s): 29-127; 2006) on structurally similar read across substance p-Cresol (CAS no 106-44-5), rabbits were treated with p-Cresol applied on rabbits in the concentration of 300 mg/kg for 24 hours. 50 % Mortality was observed in treated rabbits. Therefore, LD50 was reported to be 300mg /kg bw when rabbits were treated with p-Cresol by dermal application for 24 hours.

Further supported by experimental study summarize by Cosmetics Ingredient Expert Review Panel (International Journal of Toxicology; Volume: 25 issue: 1_suppl, page(s): 29-127; 2006) on structurally similar read across substance o-Cresol (CAS 95-48-7), rabbits were treated with o-Cresol applied on rabbits in the concentration of 890 mg/kg. 50 % Mortality was observed in treated rabbits at 890 mg/kg bw. Therefore, LD50 was considered to be 890 mg /kg bw when rabbits were treated with o-Cresol by dermal application.

Thus, based on the above studies and predictions on 2,3-dimethylphenol and its read across substances, it can be concluded that LD50 value is < 1000 mg/kg bw. Thus comparing this value with the criteria of CLP regulation, 2,3-dimethylphenol can be classified under “Category III” for acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies and predictions on 2,3-dimethylphenol, it can be concluded that 2,3-dimethylphenol can be classified under “Category IV” for acute oral toxicity and “Category III” for acute dermal toxicity and not Classified for acute Inhalation toxicity .