2-Ethylhexyl trans-4-methoxycinnamate

Endpoint summary

Description of key information

Oral:

- LD50 > 5000 mg/kg bw

Dermal:

- LD50 > 126.3 mg/kg bw

Inhalation:

- LC50 > 511 mg/m³ air

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is scientifically acceptable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Single LD10, LD50 and LD90 doses are tested on mouse (4 mice per dose). Dose is administered per os by gastric tube. Symptoms and mortality are evaluated after 24 hours and 10 days.

GLP compliance:

no

Remarks:

Prior to GLP

Test type:

standard acute method

Limit test:

no

Species:

mouse

Strain:

not specified

Sex:

not specified

Route of administration:

oral: gavage

Vehicle:

other: Gummi arabicum suspension

Doses:

6000 and 8000 mg/kg

No. of animals per sex per dose:

No data

Control animals:

not specified

Key result

Sex:

not specified

Dose descriptor:

LD50

Effect level:

> 8 000 mg/kg bw

Remarks on result:

other: Temporarily cramps were observed at 8000 mg/kg bw

Symptoms:

- Sublethal doses: Ataxia and respiratory depression

- Lethal dose: Temporarily cramps

Mortality:

- None of the animals died late (after ten days of study)

Interpretation of results:

GHS criteria not met

Conclusions:

Ethylhexyl Methoxycinnamate shows very little oral toxicity under the conditions of this study. The volume of substance that is administered is of influence on the effect. Therefore, the LD50 was set at >8000 mg/kg and Ethylhexyl Methoxycinnamate does not have to be classified according to criteria outlined in regulation 1272/2008/EC.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Similar to current guideline studies

Principles of method if other than guideline:

Method: other: BASF test

GLP compliance:

no

Test type:

other: BASF-Test

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K Tomae GmbH, Biberach, Germany
- Mean weight at study initiation: 170 g male / 190 g female
- Fasting period before study: 16 h (water ad libitum)
- Housing: Stainless steel wire mesh cages Type DK-III (Becker & Co., Castrop-Rauxel, Germany); 5 animals per cage
- Water: ad libitum
- Acclimation period: >1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12 h / 12 h

Route of administration:

oral: gavage

Vehicle:

other: 0.5 % preparation aqueous of carboxymethylcellulose

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 50 % (w/v)
- Justification for choice of vehicle: Aqueous formulation corresponds to the physiological medium

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

Doses:

5000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: min. 1/day (symptoms); min 1/day (moribund/dead animals); weighing on d3, d7, d13
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Mortality:

No deaths occurred (male/fermale)

Clinical signs:

other: no abnormalities (male/fermale)

Gross pathology:

no abnormalities (male/fermale)

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

GLP guideline study with acceptable restrictions. Restriction: documentation describes clearly methodology and results on the vapour phase, but is less clear regarding particles. Due to the low volatility of 2-Ethylhexyl 4-methoxycinnamate, particle analysis is most important. Though not easy to find, particle results are contained in the report, which is considered to be valid.

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Versuchstierzucht Winkelmann, Borchen, Germany
- Age at study initiation: 2 to 3 months
- Weight at study initiation: 160 to 220 g
- Fasting: no
- Housing: singly in macrolon cages type II
- Diet: rodent diet "Altromin 1324" ad libitum
- Water: tap water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 40 - 60 %
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: a spray tube containing the test material was placed into a water bath (20 °C). Every 10.5 seconds test material was sprayed for 0.5 seconds into a mixing chamber where it was diluted with air (20 L/min). The resulting atmospherer was guided to the inhalation chamber (stainless steel, volume 50 L). The animals were kept in plexi glass tubes with the head protruding into the inhalation chamber. Electronic measurement and regulation devices allowed to adjust the exposure concentration.
- Exposure chamber volume: 50 L
- Method of holding animals in test chamber: plexi glass tubes allowing head-nose inhalation
- Source and rate of air: air was compressed to 8 - 10 bar and cleaned from water, dust and oil. At reduced pressure, the air was guided into the mixing chamber at a rate of 20 L/min
- Method of conditioning air: water, dust and oil were removed
- System of generating particulates/aerosols: the apparatus is described above.
- Method of particle size determination:
1) TSI Laser-Velocimeter APS 3300 in the breathing zone (results not reported)
2) Impact cascade (BERNER-Kaskadenimpaktor)
- Treatment of exhaust air: the air was guided through an aerosol filters which was incinerated at the end of the exposure period.
- Temperature, humidity, pressure in air chamber: 24.6 °C; mean humidity 15.9 ± 2.7 (control), and 25 - 35 % (test material, samples I and II; cf. report, pages 47 - 49).

TEST ATMOSPHERE
- Brief description of analytical method used:
1) nominal concentration was calculated from the weight of material sprayed into the mixing chamber divided by the air volume
2) vapour: air samples were taken from the breathing zone and analysed for the volatile components (propane, butane) using GC-FID
3) Particles:
a) Particles were absorbed to Florisil in the breathing zone of the animals. After elution with ethanol, 2-Ethylhexyl 4-methoxycinnamate was determined by GC-FID using a calibration curve
b) particle size distribution:
- TSI Laser-Velocimeter APS 3300 in the breathing zone (results not reported, due to technical problems)
- Impact cascade (BERNER-Kaskadenimpaktor). Description of statistical evaluation: report, page 23.

VEHICLE
- Composition of vehicle: ethanol, propellents (propane, butane etc. Cf. report, page 11)
- Concentration of test material in vehicle: 5 % (sample I), and 2 % (sample II)
- Justification of choice of vehicle: low volatility of 2-Ethylhexyl 4-methoxycinnamate

TEST ATMOSPHERE
- Particle size distribution: log normal (report, pages 44 -46)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):
sample I: 8.29 ± 3.47 µm (report, page 43)
sample II: 3.78 ± 2.36 µm (report, page 45)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Active ingredient (a.i., report page 40)
Sample I: 497 mg/m³
Sample II: 524 mg/m³

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations: at least daily; weighing: once before treatment, and on days 3, 7 and 14 post treatment
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs; body weight; organ weights; functional tests (reflexes (visual placing, muscle tone, cornea, pupil and pinna reflexes, startle response (sound), touch-escape response, tail-pinch response, righting reflex) and grip strength)

Statistics:

Generally calculation of means ± standard deviation. Several different statistical tests to analyse differences between treatment groups.

Sex:

male/female

Dose descriptor:

LC0

Effect level:

0.511 mg/L air

Exp. duration:

4 h

Remarks on result:

other: 2-Ethylhexyl 4-methoxycinnamate

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.511 mg/L air

Exp. duration:

4 h

Remarks on result:

other: 2-Ethylhexyl 4-methoxycinnamate

Mortality:

There was no mortality (0/20), all rats survived.

Clinical signs:

other:

Body weight:

A slight reduction of body weight gain was seen in treated animals compared to controls, however without gaining a level of statistical significance.

Gross pathology:

There were no changes noted in control an dtreated animals.

Other findings:

- Other observations:
Reflexes and grip strength were not affected in treated animals.

It should be noted that 2-Ethylhexyl 4-methoxycinnamate (the active ingredient )was contained in a spray can, together with solvents and propellents in proportions listed above.

The reported concentrations represent in most instances the vapour concentrations of the volatile components, which were analysed using GC-FID. The resulting propane and butane concentrations were then used to calculate LC50 -values for the two samples, i.e. >41.8 mg/m³ (sample I) and >43.3 mg/m³ (sample II).

The volatility of the active ingredient, 2-Ethylhexyl 4-methoxycinnamate, is however low. This compound is predominantly present in the particle fraction.The particles were adsorbed to Florisil in the breathing zone of the test animals. HR 92/660 523 was then eluted from Florisil with ethanol and quantified by GC-FID, using a calibration curve of HR 92/660 523 (purity: 99.15 %). The concentration of the active ingredient was 497 and 524 mg/m³ in samples I and II, respectively (cf. report page 40). The mean concentration is therefore 511 mg/m³.

It should be noted that particle size distribution was influenced by the solvent composition. Particles with a Mass Median Aerodynimc Diameter (MMAD) of </= 3.0 µgm were considered to be respirable. Based on the results of the particle analysis, the dose of 2-Ethylhexyl 4-methoxycinnamate was 0.104 mg/L with sample 1, and 0.21 mg/L with sample 2.

   

		Sample 1	Sample 2
MMAD ± geometric SD (µm)		8.29 ± 3.47	3.78 ± 2.36
Concentration (mg/m³)		497	524
Respirability (% = 3 µm)	Mass related	21 % (measured)	40 % (measured)
	Number related	100 % (extrapolated)	99 % (extrapolated)

 

Executive summary:

In an acute inhalation toxicity study (Bayer AG, 1993), groups of young adult Wistar rats (male and female,5/sex) were exposed by inhalation route to HR 92/660 523 (2-Ethylhexyl 4-methoxycinnamate) contained in spray can at 2 and 5 %, respectively, along with considerable amounts of ethanol as solvent, and hydrocarbons as propellents. The rats were exposed for 4 hours to head only at a mean concentration of  0.511 mg 2-Ethylhexyl 4-methoxycinnamate /L. The animals then were observed for 14 days.

 

There were no findings in any test animal regarding mortality, clinical signs, changes in functional tests (reflexes and grip strength), or gross pathology except from a slightly reduced body weight gain in exposed animals, but without gaining a level of statistical significance. Therefore, the LC₀ was 0.511 mg/L in male and female rats.

 

Conclusion:

This study design is regarded to be suitable for testing the acute inhalation toxicity of low volatility compounds like 2-Ethylhexyl 4-methoxycinnamate. The study was conducted similar to OECD Test Guideline No. 403 and under GLP conditions. The acute LC_{0(4 h)} was 0.511 mg/L in male and female Wistar rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

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:

October 1977 - November 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

equivalent to OECD guideline 402 - scientifically acceptable

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

no

Remarks:

Prior to GLP

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

other: CFY

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 209 - 257 g

Type of coverage:

occlusive

Vehicle:

other: sunscreen cream

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorso-lumbar region
- % coverage: 10
- Type of wrap if used: Aluminium foil, held in place with "Sleek" waterproof plaster encircled firmly round the trunk.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Warm dilute soap solution (40 - 50 °C), followed by rinsing in clean warm water and finally blotting dry with absorbent paper.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Concentration (if solution): 2.5 - 7.5 % (Ethylhexyl Methoxycinnamate in sunscreen cream)
- Constant volume or concentration used: No

VEHICLE
- Amount(s) applied (volume or weight with unit): 5 mL/kg (maximum to be applied)

Duration of exposure:

24 hours

Doses:

126.3 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: daily
- Frequency of weighing: weekly
- Necropsy of survivors performed: Yes
- Other examinations performed: clinical signs

Statistics:

Not relevant

Preliminary study:

Not relevant

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 126.3 mg/kg bw

Remarks on result:

other: No mortalities or signs of reaction to treatment

Mortality:

None of the ten animals (5 male, 5 female) died during study.

Clinical signs:

other: No observable dermal reactions at the site of application in either the treated or control animals were seen.

Gross pathology:

Terminal atopsy findings were normal.

Other findings:

Not relevant

Interpretation of results:

other: not possible to derive a classification as no mortality was observed at dose applied

Conclusions:

The acute median lethal percutaneous dose (LD50) to rats of Ethylhexyl Methoxycinnamate was found to be greater than 126.3 mg/kg bodyweight, which was considered to be the maximum dosage.

Executive summary:

A sunscreen cream containing an end concentration of 2.5 - 7.5 % ethylhexyl methoxycinnamate is tested for acute dermal toxicity on male and female rats (5 per sex). Weight varied from 200 - 250 gram, and the maximal applicable dose is set at 5 mL/kg (representing a dose of 126.3 mg/kg bw ethylhexyl methoxycinnnamate). This dose is applied to the skin, occluded by aluminium foil and held there for 24 hours. After exposure, rats were observed for 14 days.

The study found no symptoms or mortality in any rat after 24 hours following a single dose. Loss of bodyweight was seen in female rats in week one, but this restored in week two. Weight gain of male rats was comparable to the control. Terminal autopsy findings were normal.

It was concluded that the dermal LD50 to rats for a cream containing up to 7.5 % Ethylhexyl Methoxycinnamate is greater than 126.3 mg/kg bw, which is considered to be the maximum dosage.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

In the key study (BASF SE, 1984, similar to current guideline studies, no GLP) for acute oral toxicity, no effects in rats at a dose of 5000 mg/kg were observed. This was supported by an acute oral toxicity study (Pellimont, 1968, no guideline, no GLP) in mice, in which a high single oral dose of 8000 mg/kg/day ethylhexyl methoxycinnamate caused no deaths and only slight effects (temporarily cramps). The dose of 5000 mg/kg bw was chosen as most critical value.

In the key study (Kynnoch et al, 1977, precursor of OECD 402, no GLP) for acute dermal toxicity, no effects were observed at a concentration of 126.3 mg/kg bw ethylhexyl methoxycinnamate (based on 2.5% formulation). The LD50 is therefore higher than this tested value. No supporting studies were available.

In the key study (Martins and Paulutin, 1993, OECD 403, GLP) for acute inhalation toxicity, no mortality at a concentration of 0.511 mg ethylhexyl methoxycinnamate/L air or 511 mg ethylhexyl methoxycinnamate/m³ air was observed. The LC50/LD50 is therefore higher than this tested value. No supporting studies were available.

Justification for classification or non-classification

No toxic effects (no mortality) were found in rats after oral, as well as dermal and inhalation exposure. The LD50 values were therefore established as greater than the highest doses tested. Based on these results, ethylhexyl methoxycinnamate cannot be classified as acute toxic according to the criteria for classification outlined in Annex I of 1272/2008/EC (no key parameters were established).