Icosanoic acid

Endpoint summary

Description of key information

The substance Eicosanoic acid was found to be irritating in skin and eye category.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Principles of method if other than guideline:

The prediction is done using QSAR Toolbox Version 3.1

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Type of coverage:

occlusive

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Irritation parameter:

other: Primary irritation index(PII)

Basis:

mean

Score:

1.62

Reversibility:

no data

Remarks on result:

other: Slightly irritating to the skin of rabbit.

The prediction was based on dataset comprised from the following descriptors: "Primary Irritation Index"
Estimation method: Takes average value from the 3 nearest neighbours
Domain  logical expression:Result: In Domain

(((((("a" and ("b" and ( not "c") )  )  and ("d" and ( not "e") )  )  and "f" )  and ("g" and ( not "h") )  )  and "i" )  and ("j" and "k" )  )

Domain logical expression index: "a"

Similarity boundary:Target: C(=O)(O)CCCCCCCCCCCCCCCCCCC
Threshold=50%,
Dice(Atom pairs)

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OASIS v1.1

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Michael addition OR Michael addition >> a,b-unsaturated carbonyl compounds OR Michael addition >> a,b-unsaturated carbonyl compounds >> a,b-unsatuarted aldehydes OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group >> alpha,beta-carbonyl compounds with polarized double bonds OR Schiff base formation OR Schiff base formation >> Schiff base formation with carbonyl compounds OR Schiff base formation >> Schiff base formation with carbonyl compounds >> Aldehydes OR SN2 OR SN2 >> Nucleophilic substitution at sp3 Carbon atom OR SN2 >> Nucleophilic substitution at sp3 Carbon atom >> Activated alkyl esters OR SN2 >> Nucleophilic substitution on benzylic carbon atom OR SN2 >> Nucleophilic substitution on benzylic carbon atom >> Benzylic esters OR SN2 >> Nucleophilic substitution on heterocyclic sulfenamides OR SN2 >> Nucleophilic substitution on heterocyclic sulfenamides >> Heterocyclic sulfenamides by Protein binding by OASIS v1.1

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OECD

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR Michael addition OR Michael addition >> Polarised Alkenes OR Michael addition >> Polarised Alkenes >> Polarised alkene - ketones by Protein binding by OECD

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Low (Class I) by Toxic hazard classification by Cramer (with extensions)

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as No alert found by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Phtalate (or buthyl) diesters and monoesters (Nongenotox) OR Structural alert for nongenotoxic carcinogenicity OR Substituted n-alkylcarboxylic acids (Nongenotox) by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "i"

Similarity boundary:Target: C(=O)(O)CCCCCCCCCCCCCCCCCCC
Threshold=60%,
Dice(Atom pairs)

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of logP Multicase which is >= 9.11

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of logP Multicase which is <= 9.53

Interpretation of results:

slightly irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

By primary irritation index (PII) from QSAR, skin irritation score of Eicosanoic acid was estimated to be 1.62.Based on this score it infers that the substance Eicosanoic acid was found to be slightly irritating to the skin of rabbit.

Executive summary:

By primary irritation index (PII) from QSAR, skin irritation score of Eicosanoic acid was estimated to be 1.62.Based on this score it infers that the substance Eicosanoic acid was found to be slightly irritating to the skin of rabbit.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Principles of method if other than guideline:

The prediction is done using QSAR Toolbox Version 3.1

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Duration of treatment / exposure:

1 day

Number of animals or in vitro replicates:

3-6

Irritation parameter:

other: The Modified Maximum Average Score (MMAS)

Basis:

mean

Time point:

other: 1 day

Score:

33.4

Reversibility:

not specified

Remarks on result:

other: Slightly irritating to the eyes of rabbit.

The prediction was based on dataset comprised from the following descriptors: MMAS
Estimation method: Takes average value from the 4 nearest neighbours
Domain  logical expression:Result: In Domain

(((("a" and ("b" and ( not "c") )  )  and ("d" and ( not "e") )  )  and ("f" and ( not "g") )  )  and ("h" and "i" )  )

Domain logical expression index: "a"

Similarity boundary:Target: C(=O)(O)CCCCCCCCCCCCCCCCCCC
Threshold=50%,
Dice(Atom pairs)

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OECD

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR Michael addition OR Michael addition >> Polarised Alkenes OR Michael addition >> Polarised Alkenes >> Polarised alkene - esters OR SN2 OR SN2 >> SN2 reaction at sp3 carbon atom OR SN2 >> SN2 reaction at sp3 carbon atom >> Allyl acetates and related chemicals by Protein binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as No alert found by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Halogenated benzene (Nongenotox) OR Heterocyclic Polycyclic Aromatic Hydrocarbons (Genotox) OR Structural alert for nongenotoxic carcinogenicity OR Structural alerts for both genotoxic and nongenotoxic carcinogenicity OR Substituted n-alkylcarboxylic acids (Nongenotox) by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Not classified by Oncologic Primary Classification

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Organophosphorus Type Compounds by Oncologic Primary Classification

Domain logical expression index: "h"

Parametric boundary:The target chemical should have a value of logP Multicase which is >= 8.23

Domain logical expression index: "i"

Parametric boundary:The target chemical should have a value of logP Multicase which is <= 10.1

Interpretation of results:

slightly irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

By the method of MMAS (The modified maximum average score) from QSAR,eye irritation score of Eicosanoic acid was estimated to be 33.4. On the basis of this score it infers that Eicosanoic acid showed slight irritation effect to the eyes of rabbit.(as the criteria MMAS >25 to ≤59 is irritating).

Executive summary:

By the method of MMAS (The modified maximum average score) from QSAR,eye irritation score of Eicosanoic acid was estimated to be 33.4. On the basis of this score it infers that Eicosanoic acid showed slight irritation effect to the eyes of rabbit.(as the criteria MMAS >25 to ≤59 is irritating).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation

No.of various studies were reviewed for skin irritation with Klimish rating 2 & 4 for the target as well as the read across substances for CAS: 506-30-9 considering the weight of evidence approach.

The results for target substance as well as analogues are summarized as follows

 

Sr. No	Irritation Parameter	Species	Interpretation of results	Conclusions	Sources
1	Primary irritation index (PII)	Rabbit	Slightly irritating	By primary irritation index (PII) from QSAR, skin irritation score of Eicosanoic acid was estimated to be 1.62.Based on this score it infers that the substance Eicosanoic acid was found to be slightly irritating to the skin of rabbit.	Predicted data for target CAS:506-30-9
2	Overall irritation score	Human	Mildly Irritating	Skin irritation tests performed by the method of Standard Draize test,75 mg of Stearic acid applied to the skin of human subjects for 3 days where the dosage of stearic acid was given intermittently, resulted in a mild irritation effect." The substance Stearic acid is thus considered "mildly irritating."	Experimental data from Cutaneous Toxicity for RA CAS : 57-11-4
3	Overall irritation score	Rabbit	Moderately irritating	Skin irritation tests performed by the method of Standard Draize test,500 mg of Stearic acid applied to the skin of rabbit for 24 hrs,resulted in a moderate irritation effect." The substance Stearic acid is thus considered "moderately irritating."	Experimental data from  Food and Cosmetics Toxicology for RA CAS : 57-11-4
4	Overall irritation score	Human	Moderately irritating	Skin irritation tests performed by the method of Standard Draize test,75 mg of Myristic acid applied to the skin of human subjects for 3 days where the dosage of myristic acid was given intermittently, resulted in a moderate irritation effect." The substance myristic acid is thus considered "moderately irritating."	Experimental data from Cutaneous Toxicity for RA CAS : 544-63-8

 

Based on the above results it can be concluded that substance CAS: 506-30-9 is expected to show the similar toxicological effect based on the effects observed on the other category members. Thus it is concluded that the substance Eicosanoic acid was found to be irritating (slight/ mild - moderate) to the skin of human subjects and rabbits.Based on these results it can be concluded that Eicosanoic acid is classified as a skin irritant in category 2 as per the CLP regulation.

 

Eye irritation

No.of various studies were reviewed for eye irritation with Klimish rating 2 for the target as well as the read across substances for CAS: 506-30-9 considering the weight of evidence approach.

The results for target substance as well as analogues are summarized as follows

 

Sr.No	Irritation Parameter	Species	Interpretation of results	Conclusions	Sources
1	The Modified Maximum Average Score (MMAS)	Rabbit	Slightly irritating	By the method of MMAS (The modified maximum average score) from QSAR,eye irritation score of Eicosanoic acid was estimated to be 33.4. On the basis of this score it infers that Eicosanoic acid showed slight irritation effect to the eyes of rabbit.(as the criteria MMAS >25 to ≤59 is irritating).	Predicted data from QSAR for target CAS :506-30-9
2	Overall irritation score	Rabbit	Mildly irritating	Eye irritation tests performed by the method of Standard Draize test,100 mg of Myristic acid applied to the eyes of rabbits,resulted in a mild irritation effect." The substance Myristic acid is thus considered "mildly irritating."	Experimental data from  Journal of the American College of Toxicology for RA CAS : 544-63-8

 

Based on the above results it can be concluded that substance CAS: 506-30-9 is expected to show the similar toxicological effect based on the effects observed on the other category members.Thus it is concluded that the substance Eicosanoic acid was found to be irritating (slight to mild) to the eyes of rabbit. Based on these results it can be concluded that Eicosanoic acid is classified as an eye irritant in category 2 as per the CLP regulation.

Justification for selection of skin irritation / corrosion endpoint:

By primary irritation index (PII) from QSAR, skin irritation score of Eicosanoic acid was estimated to be 1.62.Based on this score it infers that the substance Eicosanoic acid was found to be slightly irritating to the skin of rabbit.

Justification for selection of eye irritation endpoint:

By the method of MMAS (The modified maximum average score) from QSAR,eye irritation score of Eicosanoic acid was estimated to be 33.4. On the basis of this score it infers that Eicosanoic acid showed slight irritation effect to the eyes of rabbit.(as the criteria MMAS >25 to <59 is irritating).

Effects on skin irritation/corrosion: slightly irritating

Effects on eye irritation: slightly irritating

Justification for classification or non-classification

The available studies indicate that the substance Eicosanoic acid is classified as a skin and eye irritant according to CLP regulation.