2-ethoxybenzoic acid

Endpoint summary

Description of key information

By applying the weight of evidence approach, the test chemical can be considered to be not sensitizing to skin. Comparing the annotations with criteria of CLP regulation, the test chemical can be classified under the category "Not Classified".

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Weight of evidence approach based on various test chemicals

Justification for type of information:

Weight of evidence approach based on various test chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Weight of evidence approach based on various test chemicals

Principles of method if other than guideline:

Weight of evidence approach based on various test chemicals

GLP compliance:

not specified

Type of study:

other: Weight of evidence approach based on various test chemicals

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2 Ethoxybenzoic acid
- Molecular formula: C9H10O3
- Molecular weight: 166.175 g/mol
- Substance type: Organic
- Physical state: Liquid

Species:

mouse

Strain:

CBA

Sex:

female

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

1,2. 25microliters

No. of animals per dose:

groups of mice

Details on study design:

The LLNA was conducted on groups of CBA mice (7-12 weeks of age) by mean of topical application of chemical on the dorsum of both ears at a dose of 25µl or to an equal volume of relevant vehicle (Acetic acid in olive oil (4:1))only. Treatment was performed daily for 3 consecutive days. Five days after initiation of exposure all mice were injected via the tail vein with 250µl of PBS containing 20µCi of tritiatied thymidine. The mice were sacrificed 5 hours later, and draining the auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by β-scintillation counting and was reported in disintegrations /minute. An SI was calculated for each chemical group as the ratio of disintegrations/minute of the treated group to the disintegrations/minute of the concurrent vehicle control group.
A substance was classified skin sensitizer, if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3) The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value.

Positive control substance(s):

not specified

Statistics:

A substance was classified skin sensitizer, if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3) The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value.

Parameter:

SI

Value:

> 0 - < 3

Test group / Remarks:

test group

Remarks on result:

other: not sensitizing

Cellular proliferation data / Observations:

The relative potency index of the test chemical was not calculated since the SI were less than 3.

Interpretation of results:

other: not sensitizing

Conclusions:

By applying the weight of evidence approach, the test chemical can be considered to be not sensitizing to skin. Comparing the annotations with criteria of CLP regulation, the test chemical can be classified under the category "Not Classified".

Executive summary:

The skin sensitization potential of the test chemical was assessed based on the available results from the various test chemicals.

The skin sensitizing potential of the test chemicals was assessed by using the Mouse Local Lymphnode Assay. The study was conducted as per OECD 429 Guidelines.

The LLNA was conducted on groups of CBA mice (7-12 weeks of age) by mean of topical application of chemical on the dorsum of both ears at a dose of 25µl or to an equal volume of relevant vehicle (Acetic acid in olive oil (4:1))only. Treatment was performed daily for 3 consecutive days. Five days after initiation of exposure all mice were injected via the tail vein with 250µl of PBS containing 20µCi of tritiatied thymidine. The mice were sacrificed 5 hours later, and draining the auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by β-scintillation counting and was reported in disintegrations /minute. An SI was calculated for each chemical group as the ratio of disintegrations/minute of the treated group to the disintegrations/minute of the concurrent vehicle control group.

A substance was classified skin sensitizer, if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3) The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value.

The relative potency index of the test chemicals was not calculated since the SI were less than 3.

Based on the relative potency, the test chemicals were considered to be not sensitizing to mice skin.

By applying the weight of evidence approach, the test chemical can be considered to be not sensitizing to skin. Comparing the annotations with criteria of CLP regulation, the test chemical can be classified under the category "Not Classified".

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The skin sensitization potential of the test chemical was assessed based on the available results from the various test chemicals.

The skin sensitizing potential of the test chemicals was assessed by using the Mouse Local Lymphnode Assay. The study was conducted as per OECD 429 Guidelines.

The LLNA was conducted on groups of CBA mice (7-12 weeks of age) by mean of topical application of chemical on the dorsum of both ears at a dose of 25µl or to an equal volume of relevant vehicle (Acetic acid in olive oil (4:1))only. Treatment was performed daily for 3 consecutive days. Five days after initiation of exposure all mice were injected via the tail vein with 250µl of PBS containing 20µCi of tritiatied thymidine. The mice were sacrificed 5 hours later, and draining the auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by β-scintillation counting and was reported in disintegrations /minute. An SI was calculated for each chemical group as the ratio of disintegrations/minute of the treated group to the disintegrations/minute of the concurrent vehicle control group.

A substance was classified skin sensitizer, if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3) The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value.

The relative potency index of the test chemicals was not calculated since the SI were less than 3.

Based on the relative potency, the test chemicals were considered to be not sensitizing to mice skin.

By applying the weight of evidence approach, the test chemical can be considered to be not sensitizing to skin. Comparing the annotations with criteria of CLP regulation, the test chemical can be classified under the category "Not Classified".

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

By applying the weight of evidence approach, the test chemical can be considered to be not sensitizing to skin. Comparing the annotations with criteria of CLP regulation, the test chemical can be classified under the category "Not Classified".