Fatty acids, coco, iso-Bu esters

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) and the source substance FATTY ACIDS, C16-18, ISOBUTYL ESTERS (CAS 85865-69-6) are both Short Chain Alcohol Esters (SCAE C2-C8) composed by a fatty acid (C16-C18) and a C4 alcohol (isobutanol).
The source and the target substance show therefore the same reactive groups and a similar composition. A read-across to the source is therefore justified.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with organic acids (e. g. stearic acid) in the presence of an acid catalyst. The esterification reaction is started by a transfer of a proton from the acid catalyst to the acid to form an alkyloxonium ion. The carboxylic acid is protonated on its carbonyl oxygen followed by a nucleophilic addition of a molecule of the alcohol to a carbonyl carbon of acid. An intermediate product is formed. This intermediate product loses a water molecule and proton to give an ester. Monoesters are the final product of esterification.

3. ANALOGUE APPROACH JUSTIFICATION
Since both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with an organic acid and therefore share similar/overlapping structural features and functional groups, it is justified to use a read across approach. The source substance has been registered already and its inhalation acute toxicity has been investigated using a grouping of substance and read across approach. All available acute inhalation toxicity studies within this category resulted in an acute inhalation LC50 > 5 mg/L air. It has been concluded that no adverse effects are observed for Fatty acids, C16-18, isobutyl esters (CAS No. 85865-69-6).
The same behaviour is predicted for the target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) .

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

21 Mai - 04 Jun 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP-guideline studyGLP guideline study, tested with the source substance CAS 67762-63-4. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Crl:WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approximately 10-12 weeks old
- Weight at study initiation: max. ± 20% of the sex mean
- Housing: before exposure: Group housing of five animals per sex per cage in labelled Makrolon cages (type IV; height 18 cm) containing sterilised sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom); after exposure: Group housing of maximally three animals per sex per cage as described above, except that a paper sheet was introduced into the cage covering the bedding and cage enrichment to prevent suffocation in case of bad health condition. At the end of the day of exposure the paper sheet was removed.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany) except during exposure to the test substance.
- Water: Free access to tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range: 19.6 – 23.3)
- Humidity (%): 40-70 (actual range: 38 - 62)
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The design of the exposure chamber is based on the flow past nose-only inhalation chamber (Am. Ind. Hyg Assoc. J. 44(12): 923-928, 1983).
- Method of holding animals in test chamber: animal ports
- System of generating particulates/aerosols: An aerosol was generated by nebulization of the test substance by means of a nebulizer (type 950, Hospitak Inc., Lindenhurst, NY, USA)
- Method of particle size determination: Amounts of test substance collected were measured gravimetrically. Subsequently the Mass Median Aerodynamic Diameter (MMAD) and the Geometric Standard Deviation (GSD) were determined
- Treatment of exhaust air: From the exposure chamber the test atmosphere was passed through a filter before it was released to the exhaust of the fume hood.


TEST ATMOSPHERE
- Brief description of analytical method used: Samples were drawn through a glass fiber filter (type APFC04700, Millipore, Billerica, MA, USA). The collected amount of test substance in the air sample was measured gravimetrically. Sample volumes were measured by means of a dry gas meter (type G 1.6, Actaris Meterfabriek B.V., Dordrecht, The Netherlands).
- Samples taken from breathing zone: yes

VEHICLE
- The test substance was used as delivered by the sponsor

TEST ATMOSPHERE
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The Mass Median Aerodynamic Diameter (MMAD) and geometric standard deviation (GSD) were determined twice. The MMAD was 3.4 µm (GSD 1.5) and 4.1 µm (GSD 1.6).

CLASS METHOD
- Rationale for the selection of the starting concentration: The target concentration was based on the hazard categories for dust and mists specified in the Globally Harmonized System of Classification of Chemicals (GHS), United Nations, New York and Geneva, 2003.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetrically

Duration of exposure:

4 h

Concentrations:

The mean actual concentration was 5.3 ± 0.7 mg/L. The nominal concentration was 16.2 mg/L. The generation efficiency (ratio of actual and nominal concentration) was 33%.

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality/Viability: Twice daily; Clinical signs during exposure: Three times during exposure for mortality, behavioural signs of distress and effects on respiration. Clinical signs after exposure: Twice (at 1 and at 3 hours after exposure) on the day of dosing (day 1) and once daily thereafter, until day 15. The symptoms were graded according to fixed scales and the time of onset, degree and duration were recorded: Maximum grade 4: grading slight (1) to very severe (4); Maximum grade 3: grading slight (1) to severe (3); Maximum grade 1: presence is scored (1); Body weights Days 1 (pre-administration), 2, 4, 8 and 15.
- Necropsy of survivors performed: yes

Statistics:

No statistical analysis was performed (the method used was not intended to calculate a LC50 value).

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.3 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: No clinical signs were noted during or after exposure.

Body weight:

Body weight gain in males and females was within the range expected for rats of this strain and age used in this type of study.

Gross pathology:

Macroscopic post mortem examination of the animals revealed pale discolouration of the lungs of one female. No other abnormalities were noted in any of the animals.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

DSD: not classified
GHS: not classified

Cross-reference 2

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

28 Apr - 12 May 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP guideline study, tested with the source substance CAS 10233-13-3. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Crl:WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approximately 12 weeks old
- Weight at study initiation: max. ± 20% of the sex mean
- Housing: before exposure: Group housing of five animals per sex per cage in labelled Makrolon cages (type IV; height 18 cm) containing sterilised sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom); after exposure: Group housing of maximally three animals per sex per cage as described above, except that a paper sheet was introduced into the cage covering the bedding and cage enrichment to prevent suffocation in case of bad health condition. At the end of the Day of exposure the paper sheet was removed.
- Diet: Pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany) except during exposure to the test substance, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range: 19.8 – 21.4)
- Humidity (%): 40-70 (actual range: 37 - 63)
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The design of the exposure chamber is based on the flow past nose-only inhalation chamber (Am. Ind. Hyg Assoc. J. 44(12): 923-928, 1983).
- Method of holding animals in test chamber: animal ports
- System of generating particulates/aerosols: An aerosol was generated by nebulization of the test substance by means of a nebulizer (type 950, Hospitak Inc., Lindenhurst, NY, USA)
- Method of particle size determination: Amounts of test substance collected were measured gravimetrically. Subsequently the Mass Median Aerodynamic Diameter (MMAD) and the Geometric Standard Deviation (GSD) were determined
- Treatment of exhaust air: From the exposure chamber the test atmosphere was passed through a filter before it was released to the exhaust of the fume hood.
- Temperature, humidity, pressure in air chamber: The temperature of the atmosphere was between 20.8 and 21.2 °C and relative humidity was between 23 and 25%. These conditions were considered appropriate for this relatively short 4 hours exposure duration.

TEST ATMOSPHERE
- Brief description of analytical method used: Samples were drawn through a glass fiber filter (type APFC04700, Millipore, Billerica, MA, USA). The collected amount of test substance in the air sample was measured gravimetrically. Sample volumes were measured by means of a dry gas meter (type G 1.6, Actaris Meterfabriek B.V., Dordrecht, The Netherlands).
- Samples taken from breathing zone: yes

VEHICLE
- The test substance was used undiluted.

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMAD and GSD were determined twice, MMAD was 4.0 µm (GSD 2.4) and 5.2 µm (GSD 1.9).

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: The target concentration was based on the hazard categories for dust and mists specified in the Globally Harmonized System of Classification of Chemicals (GHS), United Nations, New York and Geneva, 2003.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetrically

Duration of exposure:

4 h

Concentrations:

The mean actual concentration was 5.3 ± 0.3 mg/L. The nominal concentration was 7.1 mg/L. The generation efficiency (ratio of actual and nominal concentration) was 75%. Data obtained from the opacity monitor showed that the aerosol was sufficiently stable.

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality/Viability: Twice daily; clinical signs during exposure: three times during exposure for mortality, behavioural signs of distress and effects on respiration. Clinical signs after exposure: twice (at 1 and at 3 hours after exposure) on the day of dosing (day 1) and once daily thereafter, until day 15. The symptoms were graded according to fixed scales and the time of onset, degree and duration were recorded: maximum grade 4: grading slight (1) to very severe (4); maximum grade 3: grading slight (1) to severe (3); maximum grade 1: presence is scored (1); body weights Days 1 (pre-administration), 2, 4, 8 and 15.
- Necropsy of survivors performed: yes

Statistics:

No statistical analysis was performed (the method used was not intended to calculate a LC50 value).

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.3 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred.

Clinical signs:

other: Hunched posture was observed in all animals 1 and 3 hours after exposure. No clinical signs were noted during exposure.

Body weight:

Body weight gain in males and females was within the range expected for rats of this strain and age used in this type of study.

Gross pathology:

No abnormalities were observed at macroscopic post mortem examination of the animals.

The inhalatory 4-h LC₅₀value of isopropyl laurate in Wistar rats was found to exceed 5 mg/L.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Cross-reference 3

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

03 Jun - 17 Jun 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP guideline study, tested with the source substance CAS 26399-02-0. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Version / remarks:

adopted in 2009

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Crl:WI (Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: 9 weeks old
- Weight at study initiation: max. ± 20% of the sex mean
- Housing: Before exposure-Group housing of maximally 5 animals per sex per cage in labeled Makrolon cages (type IV; height 18cm.) containing sterilised sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, UK). After exposure - Group housing as described above, maximally 3 animals per sex per cage.
- Diet: pelleted rodent diet (SM R/M-Z from SSNIFF Spezialdiäteb GmbH, Soest, Germany), ad libitum except during exposure to the test substance.
- Water: tap-water, ad libitum except during exposure to the test substance.
- Acclimation period: 5 days before the start of treatment under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 3
- Humidity (%): 40-70
- Air changes (per hr): 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: To:

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION

- Exposure apparatus: The design of the exposure chamber is based on the flow past nose-pnly inhalation chamber (Am.Ind.Hyg Assoc.J. 44(12): 923-928, 1983). The chamber consists of animal sections with eight animal ports each. Each animal port has its own atmosphere inlet and exhaust outlet.

- Method of holding animals in test chamber: Animals are placed in restraining tubes, which is then connected to the exposure chamber.

- Source and rate of air: The theoretical air flow was at least 1L/min.

- System of generating aerosols: An aerosol was generated by nebulization of the test substance by means of a nebulizer (type 950,
Hospitak Inc., Lindenhurst, NY, USA). The primary aerosol was diluted with pressurized air before it entered the exposure chamber. The mean total airflow was 16 L/min. From the exposure chamber the test atmosphere was passed through a filter before it was released to the exhaust of the fume hood.

- Method of conditioning air: The direction of the flow of the test atmosphere guarantees a freshly generated atmosphere for each individual animal.

- Temperature, humidity, pressure in air chamber: The temperature of the atmosphere was between 20.0 and 20.7 °C and relative humidity was between 28 and 30%. These conditions were considered appropriate for the relatively short 4 hours exposure duration.


TEST ATMOSPHERE
- Brief description of analytical method used: Samples were drawn through a glass fiber filter (type APFC04700, Millipore, Billerica, MA, USA). The collected amount of test substance in the air sample was measured gravimetrically. Sample volumes were measured by means of a dry gas meter (type G 1.6, Actaris Meterfabriek B.V., Dordrecht, The Netherlands).
- Samples taken from breathing zone: yes


VEHICLE
- The test substance was used as delivered by the sponsor

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMAD was 2.5 µm (GSD 2.4) and 2.6 µm (GSD 2.3).

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: Target concentrations were based on the cut off concentration values specified in the UN and EC classification guidelines.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetrically

Duration of exposure:

4 h

Concentrations:

The mean actual concentration was 5.7 ± 0.4 mg/L. The nominal concentration was 15.4 mg/L. The generation efficiency (ratio of actual and nominal concentration) was 37%. Data obtained from the opacity monitor showed that the aerosol was sufficiently stable.

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: twice daily
Clinical signs: twice on the day of dosing (1 and 3 hours after exposure); daily thereafter until day 15
Body weight: recorded on day1 (pre-exposure), 2, 4, 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology
All animals were sacrificed at the end of the observation period by an intraperitoneal injection with Euthasol® (AST Farma BV, Oudewater, The Netherlands).

Statistics:

No statistical analysis was performed (the method used was not intended to calculate a LC50 value).

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.7 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: No mortalities occured. Apart from hunched position observed in all on day2 after exposure, no further signs of adverse toxicity were observed until the end of the 14 day observation period.

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 15.4 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortalities occured during the observation period.

Clinical signs:

other: Hunched posture was shown by all animals on Day 2 after exposure. No clinical signs were noted during exposure.

Body weight:

Body weight gain in males and females were within the range expected for rats of this strain and age used in this type of study.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, coco, iso-Bu esters

EC Number:

294-304-2

EC Name:

Fatty acids, coco, iso-Bu esters

Cas Number:

91697-43-7

Molecular formula:

Not available for UVCB substances

IUPAC Name:

Fatty acids, coco, iso-Butyl esters

Test material form:

liquid

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.3 mg/L air (analytical)

Based on:

other: LC50 value chosen as worst case value from all study results available

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The source substance has been registered already and its inhalation acute toxicity has been investigated using a grouping of substance and read across approach. All available acute oral toxicity studies within this category resulted in an acute oral LC50 > 5 mg/L air. It has been concluded that no adverse effects are observed for Fatty acids, C16-18, isobutyl esters (CAS No. 85865-69-6).
The same behaviour is predicted for the target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) .

Executive summary:

The target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) and the source substance FATTY ACIDS, C16-18, ISOBUTYL ESTERS (CAS 85865-69-6) are both Short Chain Alcohol Esters (SCAE C2-C8) composed by a fatty acid (C16-C18) and a C4 alcohol (isobutanol).

The source substance has been registered already and its inhalation acute toxicity has been investigated using a grouping of substance and read across approach. All available acute oral toxicity studies within this category resulted in an acute oral LC50 > 5 mg/L air. It has been concluded that no adverse effects are observed for Fatty acids, C16-18, isobutyl esters (CAS No. 85865-69-6).

The same behaviour is predicted for the target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) .