Hexanoic acid, 3,5,5-trimethyl-, 1,1'-[2-ethyl-2-[[(3,5,5-trimethyl-1-oxohexyl)oxy]methyl]-1,3-propanediyl] ester

Endpoint summary

Description of key information

Oral
Key, LD50 oral > 2000 mg/kg bw (test item), Sanders, 2013
Supporting, LD 50 oral > 2000 mg/kg bw  (EC 234-392-1), Clouzeau, 1990
Supporting, LD50 oral >2000 mg/kg bw  (CAS 85116-93-4), Potokar, 1983
Supporting, LD50 oral >2000 mg/kg bw  (CAS 68424-31-7), Robinson, 1991
Supporting, LD50 oral >2000 mg/kg bw  CAS 131459-39-7,  Allen, 1999
Dermal
Key, LD50 dermal > 2000 mg/kg bw (test item), Sanders, 2013
Supporting,  LD50 dermal: >2000 mg/kg bw (EC 234-392-1), Blanset, 1997
Supporting, LD50 dermal: >2000 mg/kg bw (CAS 131459-39-7), Allen, 1999
Inhalation
Key, LD50 inhalation: > 5100 mg/m3 air (aerosol)  (CAS 68424-31-7), Parr-Dobrzanski, 1994

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-06-06 to 2013-06-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in accordance with recognised guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 152-163 g
- Fasting period during the study: Animals were fasted for overnight period before test item administration and for approximately 3-4 h after dosing.
- Housing: Animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes
- Diet: Food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK), ad libitum
- Water: Mains drinking water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19-25 °C
- Humidity: 30-70 %
- Air changes: 15 air changes/hour
- Photoperiod: 12 h dark / 12 h light

IN-LIFE DATES: From: 2013-06-06 To: 2013-06-27

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

SPECIFIC GRAVITY OF TEST ITEM: 0.932

MAXIMUM DOSE VOLUME APPLIED: 2.15 mL/kg bw

Doses:

- Sighting test: 2000 mg/kg bw
- Main test: 2000 mg/kg bw

No. of animals per sex per dose:

- Sighting test: 1 female/dose
- Main test: 4 females/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: Clinical observations were made 0.5, 1, 2, and 4 h after dosing and then daily for fourteen days. Morbidity and mortality checks were made twice daily.
- Frequency of weighing: Individual body weights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
- Necropsy of survivors performed: Yes; at the end of the observation period the animals were killed by cervical dislocation and were subjected to a macroscopic examination.

Statistics:

Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD50) of the test item was made.

Preliminary study:

- No mortality or signs of systemic toxicity were noted during the observation period.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality was observed.

Mortality:

No mortality was observed.

Clinical signs:

other: No signs of systemic toxicity were noted during the observation period.

Gross pathology:

No abnormalities were observed at necropsy.

Other findings:

None

Individual body weights and body weight changes:

Dose level mg/kg	Animal number and sex	Body weight (g) at Day			Body weight gain (g) during week
		0	7	14	1	2
2000	1-0	156	168	187	12	19
	2-1	152	166	182	14	16
	2-2	163	171	208	8	37
	2-3	158	168	190	10	22
	2-4	153	166	183	13	17

Interpretation of results:

not classified

Conclusions:

Under the test conditions, the oral LD50 for test item is higher than 2000 mg/kg bw in female rats therefore it is not classified according to CLP Regulation (EC) No. 1272/2008.

Executive summary:

Test Guidance

OECD Guideline 420 and EC Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

 

Method and materials

Groups (4 females/dose) of Wistar rats (RccHan™:WIST) were given a single oral (gavage) dose of the test material at 2000 mg/kg bw. Animals were then observed for mortality, clinical signs and bodyweights for 14 days and were all sacrificed for macroscopic examination. A sighting test was conducted with one female at the dose level of 2000 mg/kg bw to determine the dose for main study.

 

Results

No mortality was observed. No signs of systemic toxicity were noted during the observation period. All animals showed expected gains in body weight over the observation period. No abnormalities were observed at necropsy. In this study, the oral LD50 of the test item was considered to be higher than 2000 mg/kg bw in female rats.

 

Conclusion

Under the test conditions, the oral LD50 is higher than 2000 mg/kg bw in female rats, therefore the substance is not classified according to CLP Regulation (EC) No. 1272 /2008.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

One reliable study (k=1)performed on substance itself, supported by two reliable studies (k=2) on read-across substances. In addition, there are a further two studies for read across substances where the reliability could not be determined (k=4).

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

March 22nd, 1994 - April 05th, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

: No details on test material

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Alpk:APfSD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Alderly Park, Cheshire, UK
- Age at study initiation: approx. 7 weeks

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION

- Source and rate of air: dried and filtered air
- System of generating aerosols: glass concentric jet atomiser
- Method of particle size determination: Marple Cascade Impactor
- Temperature, humidity, pressure in air chamber: 20 l/min


TEST ATMOSPHERE
- Brief description of analytical method used: gravimetrically
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 1.51 µm/2.51


CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: maximum concentration of 5 mg/l (OECD limit test)

Analytical verification of test atmosphere concentrations:

yes

Remarks:

particulate concentrations of the test atmospheres close to the animals breathing zone were measured gravimetrically

Duration of exposure:

4 h

Concentrations:

5.0 mg/l (nominal)
5.10 mg/l (analytical)

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily, recording of body weight on days 1, 2, 3, 8 and 15
- Necropsy of survivors performed: yes

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.1 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

None

Clinical signs:

other: Reversible and consistent with the use of restraint for exposure to the test atmosphere. Hunched position, chromodacryorrhea, piloerection, stains around the nose and wet fur.

Body weight:

Body weight gain was within normal limits.

Gross pathology:

No treatment related gross pathological findings.

Other findings:

- Organ weights: Lung weight was within normal limits.

Bodyweight, bodyweight gain and lung weights for all treated animals were within normal limits and there were no gross pathological findings. In general, animals showed rapid recovery from effects seen. The medium lethal concentration in the rat is considered to be in excess of 5.1 mg/L.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

The read-across justification is based primarily on structural and chemical similarities (i.e., polyol esters) that result in “close commonalities” in physicochemical and toxicological properties.

The substance and analogues contain a polyhydroxy alcohol and at least one ester function. They have a similar number of ester functions (3 or 4), but with a range in length of the carboxylic acid function (C5-C10), and the extent of unsaturation of the carboxylic acid group. These structural differences are expected to result in a similar range of physicochemical properties, especially partition coefficient and water solubility, and their associated environmental fate and toxicological properties.

The group of substances have low water solubility and vapour pressure, high lipophilicity, and similar environmental fate properties (biodegradation, photodegradation, hydrolysis and fugacity). Mammalian toxicity data for acute, repeated-dose and genetic toxicity support grouping of these substances. The high molecular weight (>500) of the fully esterified substance should limit uptake from the gastrointestinal tract, and thus similar toxicity is expected.

Details are attached in Section 13.

Reason / purpose for cross-reference:

read-across source

Duration of exposure:

h

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.1 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

None

Clinical signs:

other: Reversible and consistent with the use of restraint for exposure to the test atmosphere. Hunched position, chromodacryorrhea, piloerection, stains around the nose and wet fur.

Body weight:

Body weight gain was within normal limits.

Gross pathology:

No treatment related gross pathological findings.

Other findings:

- Organ weights: Lung weight was within normal limits.

Bodyweight, bodyweight gain and lung weights for all treated animals were within normal limits and there were no gross pathological findings. In general, animals showed rapid recovery from effects seen. The medium lethal concentration in the rat is considered to be in excess of 5.1 mg/L.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Reference 3

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating conc.

Value:

5 100 mg/m³ air

Quality of whole database:

One reliable study (k=2) performed on a read across substance is available.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-06-12 to 2013-06-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in accordance with recognised guidelines.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Oxon, UK.
- Age at study initiation: 8-12 Weeks
- Weight at study initiation: 200 g
- Fasting period before study: None
- Housing: Animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24 h exposure period and in groups of five, by sex, for the remainder of the study.
- Diet: Food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK), ad libitum
- Water: Mains drinking water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 °C
- Humidity (%): 30-70 %
- Air changes: 15 air changes/hour
- Photoperiod: 12 h dark / 12 h light

IN-LIFE DATES: From: 2013-06-12 To: 2013-06-26

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: Back and flanks
- % coverage: ca. 10% of the total body surface area
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi occluded with a piece of self adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Cotton wool moistened with arachis oil BP to remove any residual test item.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw
- Specific gravity of test item: 0.932
- Dose volume: 2.15 mL/kg bw
- Constant volume or concentration used: Yes

Duration of exposure:

24 h

Doses:

Single dose level of 2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: Animals were observed for deaths or overt signs of toxicity 0.5, 1, 2 and 4 h after dosing and subsequently once daily for 14 days.
- Frequency of weighing: Individual body weights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: Yes, at the end of the study the animals were killed by cervical dislocation and subjected for macroscopic examination.

Statistics:

Using the mortality data obtained, an estimate of the acute dermal median lethal dose (LD50) of the test item was made.

Preliminary study:

Not applicable.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Remarks on result:

other: no mortality was observed.

Mortality:

- No mortality was observed.

Clinical signs:

other: - No signs of systemic toxicity were noted during the observation period. - There were no signs of dermal irritation.

Gross pathology:

- No abnormalities were noted at necropsy

Other findings:

None

None

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the test conditions, the acute dermal LD50 is higher than 2000 mg/kg bw in rats therefore the substance is not classified according to CLP Regulation (EC) No. 1272/2008.

Executive summary:

Test Guidance

OECD Guideline 402 and EC Method B.3 (Acute Toxicity Dermal)

Method and materials

A group of Wistar (RccHan^TM:WIST) rats (5/sex/dose) were given a single dermal application of test item at 2000 mg/kg bw. The test item was placed directly on back and flanks of the skin representing approximately 10 % of the total body surface of the animals. The test site was then covered by a semi-occlusive dressing for 24 h. Animals were then observed for mortality, clinical signs and bodyweights for 14 days.

Results

No mortality and no clinical signs were observed during the study. There were no signs of dermal irritation. All animals showed expected gains in body weight over the observation period. No macroscopic abnormalities were observed at necropsy. The combined dermal LD50 was considered to be higher than 2000 mg/kg bw in rats.

Conclusion

Under the test conditions, the acute dermal LD50 is higher than 2000 mg/kg bw in rats therefore it is not classified according to CLP Regulation (EC) No. 1272/2008.

 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

One reliable study (k=1)performed on substance itself, supported by two reliable studies (k=2) on read-across substances.

Additional information

Data for acute oral and dermal toxicity are available from studies performed using the substance itself. For acute inhalation toxicity, data are not available for the substance itself, but use is made of read-across. In addition, read-across data are available for acute oral and dermal toxicity and these data are used to support the studies on the substance itself.

Read-across to the toxicological properties of fatty acid polyols (Fatty acids, C5-9, esters with pentaerythritol (EC 270-290-3, CAS 68424-30-6)) and Decanoic acid, ester with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol octanoate (EC 234-392-1, CAS 11138-60-6)) and their analogues is applicable based on the similarity in structure and physico-chemical properties.

The substances with CAS No. 131459-39-7, CAS 85116 -93 -4 and CAS 68424 -31 -7 are structural analogues of one of the read-across substances (CAS No. 68424-30-6) and can therefore be used for read-across.

The justification for read-across is presented in Section 13 Assessment reports- Read-across justification.

Acute Oral toxicity:

One reliable study is available. In this study (Sanders, 2013) performed under GLP according to OECD TG 420 and EC Method B.1 bis, female Wistar rats (total of five animals) were dosed by gavage at 2000 mg/kg bw of the substance and observed for a period of 14 days. No mortality was observed. No signs of systemic toxicity were noted during the observation period. All animals showed expected gains in body weight over the observation period. No abnormalities were observed at necropsy. In this study, the oral LD50 of the test item was considered to be higher than 2000 mg/kg bw in female rats.

 

Treatment of rats with 2000 mg/kg bw with EC 234 -392 -1 (Clouzeau, 1990) and CAS No. 85116-93-4 (Potokar 1983) revealed the oral LD50 to be higher than 2000 mg/kg bw.

 

The study conducted with CAS No. 68424-31-7 (Robinson, 1991) had the same limitations (reduced animal number), but revealed similar results. An initial weight loss was observed after treatment of rats with 2000 mg/kg bw, but this effect was completely reversible and the animals showed subsequently normal body weight gain.

Treatment of rats with 2000 mg/kg bw of CAS 131459-39-7 (Allen, 1999) did not cause adverse effects in a study conducted according to OECD Guideline 423.

 

Acute Dermal toxicity:

One reliable study is available. In this study (Sanders, 2013) performed under GLP according to OECD TG 402 and EC Method B.3, Wistar rats (5/sex) were given a single dermal application of the substance at 2000 mg/kg bw under semi-occlusive conditions for 24 hours. Animals were then observed for 14 days. No mortality and no clinical signs were observed during the study. There were no signs of dermal irritation. All animals showed expected gains in body weight over the observation period. No macroscopic abnormalities were observed at necropsy. The combined dermal LD50 was considered to be higher than 2000 mg/kg bw in rats.

In supporting studies, the semi-occlusive application of 2000 mg/kg bw of EC 234 -392 -1 (Blanset, 1997) or CAS 131459-39-7 (Allen, 1999) for 24 h (according to OECD 402) did not cause any adverse effects in rats.

 

Acute Inhalation toxicity:

Rats were exposed nose only for 4 hours to approx. 5.1 mg/L CAS No. 68424-31-7 (analytical concentration) of the aerosol of the test material (Parr-Dobrzanski, 1994). No mortality occurred and no signs of systemic toxicity were observed. Other effects observed (hunched posture, chromodacryorrhea, piloerection, stains around the nose and wet fur) were reversible. Body weight gain and lung weight were within normal limits and there were no treatment related gross pathological findings.

Justification for selection of acute toxicity – oral endpoint
K=1 study performed on substance itself

Justification for selection of acute toxicity – inhalation endpoint
K=2 study performed on read-across substance

Justification for selection of acute toxicity – dermal endpoint
K=1 study performed on substance itself

Justification for classification or non-classification

The oral LD50 is higher than 2000 mg/kg bw in female rats, therefore the substance is not classified according to CLP Regulation (EC) No. 1272 /2008 for acute oral toxicity.

 

The acute dermal LD50 is higher than 2000 mg/kg bw in rats therefore the substance is not classified according to CLP Regulation (EC) No. 1272/2008 for acute dermal toxicity.

 

Based on data available for a read-across substance where the LC50 (4 h) was > 5.1 mg/L, the substance is not classified according to CLP Regulation (EC) No. 1272/2008 for acute inhalation toxicity.