Benzaldehyde

Endpoint summary

Description of key information

Several studies on the acute toxicity of the test substance are available. Based on a weight of evidence, a conclusion on the acute oral toxicity of the test substance is drawn.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to OECD guideline but not in compliance with GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann
- Age at study initiation: 9 weeks
- Weight at study initiation: 166 grams (mean)
- Fasting period before study: 16 hours
- Housing: 5 animals/cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period:


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±1.5°C
- Humidity (%): 60±5%
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

None stated

Doses:

0.8, 1.0, 1.1, 1.2, 1.3, 1.5 and 1.8 mL/kg

No. of animals per sex per dose:

10

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: 2 times/day
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight and histopathology

Statistics:

Probit analysis

Sex:

male

Dose descriptor:

LD50

Effect level:

ca. 1 430 mg/kg bw

Based on:

test mat.

95% CL:

>= 1.33 - <= 1.54

Mortality:

Dose: 0.8 mL/kg. Mortality: 0/10 animals.
Dose: 1.0 mL/kg. Mortality: 1/10 animals.
Dose: 1.1 mL/kg. Mortality: 1/10 animals.
Dose: 1.2 mL/kg. Mortality: 5/10 animals.
Dose: 1.3 mL/kg. Mortality: 7/10 animals.
Dose: 1.5 mL/kg. Mortality: 9/10 animals.
Dose: 1.8 mL/kg. Mortality: 10/10 animals.

Clinical signs:

other: Sedation, staggered, weightloss, rough coat, illness were observed.

Gross pathology:

No information provided

Other findings:

No information provided

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute LD50 in an acute oral toxicity study with the test substance in rats appeared to be approximately 1430 mg/kg bw.

Executive summary:

This study was conducted according to a method which equivalent or similar to OECD guideline 401 using rats.

The acute LD50 in an acute oral toxicity study with the test substance in rats appeared to be approximately 1430 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 430 mg/kg bw

Quality of whole database:

2 (reliable with restrictions)

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

Study period:

From 31 March to 16 April 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study run to a method comparable with current guidelines and to GLP.

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

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L’Arbresle Cedex, France
- Age at study initiation: Young adult animals (approximately 12 weeks old)
- Housing: Group housing of five animals per sex per cage in labelled Macrolon cages (type IV; height 18 cm) containing sterilised sawdust as bedding material and paper as cage-enrichment.
- Diet (e.g. ad libitum): Free access to pelleted rodent diet except during exposure to the test substance.
- Water (e.g. ad libitum): Free access to tap water except during exposure to the test substance.
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 ℃ (actual range: 20.0 – 21.7 ℃)
- Humidity (%): 40-70% (actual range: 34 - 57%)
- Air changes (per hr): 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours artificial fluorescent light and 12 hours darkness per day

IN-LIFE DATES: From: 31 March 2010 To: 16 April 2010

No additional data

Route of administration:

other: aerosol/vapor mixture

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. The chamber consisted of three animal sections with eight animal ports each.
- Method of holding animals in test chamber: The animals were placed in restraining tubes and connected to the animal ports.
- Source and rate of air: The mean total airflow was 29 and 54 L/min. for the 5 and 1 mg/L exposure groups respectively.
- System of generating particulates/aerosols: An aerosol/vapor mixture was generated by nebulization of the test substance by means of a nebulizer (type 950, Hospitak Inc., Lindenhurst, NY, USA). The primary aerosol/vapor mixture was diluted with pressurized air before it entered the exposure chamber.
- Method of particle size determination: For 5 mg/L, two representative droplet size distribution characterizations were conducted for the aerosol during exposure. The samples were drawn (2 L/min) from the test atmosphere through a tube mounted in one of the free animal ports of the middle section of the exposure chamber. The samples were collected with an 8 stage Marple personal cascade impactor containing fiber glass filters and a fiber glass back-up filter. Amounts of test substance collected were measured gravimetrically. Subsequently the Mass Median Aerodynamic Diameter (MMAD) and the Geometric Standard Deviation (GSD) were determined.
For 1 mg/L, the test atmosphere almost completely consisted of a vapor and therefore no droplet size characterization was conducted.
- 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 19.9 and 21.7 ℃ and relative humidity was between 22.4 and 25.5%.

TEST ATMOSPHERE
- Brief description of analytical method used: A small stream of the test atmosphere was drawn from the test atmosphere through a tube mounted in one of the free animal ports of the middle section of the exposure chamber. The tube was heated to at least 200 ℃ to avoid condensation of the test atmosphere. The tube was connected to a gas cell, which was heated to 200 ℃ and mounted in a FTIR spectrophotometer (method developed under NOTOX project 493452). Both phases of the aerosol/vapor mixture were measured completely by the FTIR.
- Samples taken from breathing zone: no

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): For 5 mg/L, the Mass Median Aerodynamic Diameter (MMAD) and geometric standard deviation (gsd) were determined twice at 4.7 μm (gsd 1.8) and 4.5 μm (gsd 1.5), respectively. For 1 mg/L, the test atmosphere almost completely consisted of a vapor and therefore no droplet size characterization was conducted.

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 UN and EC classification guidelines. The upper limit of the guideline concentration was increased with 10% in order to avoid the mean actual concentration to fall below the cut off value due to experimental variation. Three animals of each sex were exposed in a limit test for 4 hours to a target concentration of the test substance of 5.5 mg/L. Based on mortality at 5.5 mg/L, an additional group of 6 females (most susceptible sex) was exposed to 1.1 mg/L.

No additional data

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

The mean actual measured concentration was 5.39 ± 0.96 mg/L at 5 mg/L and 1.18 ± 0.42 mg/L at 1 mg/L.

No. of animals per sex per dose:

Three animals per sex were exposed in a limit test; 6 females were exposed to an additional dose

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Body weights: On Days 1 (pre-treatment), 2, 4, 8 and 15 and at death (if found dead or sacrificed after day 1); Clinical signs: Three times during exposure for mortality, behavioural signs of distress and effects on respiration, and twice (at 1 and at 3 hours after exposure) on the day of dosing (Day 1) and once daily thereafter, until Day 15.
- Necropsy of survivors performed: yes
- Other examinations performed: Mortality/Viability

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:

1 - 5 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All females and one male were found dead or sacrificed moribund within approximately 2 and 24 hours after exposure to 5 mg/L. No mortality occurred at 1 mg/L.

Clinical signs:

other: Clinical signs noted among most animals after exposure at 5 mg/L included lethargy, flat/hunched posture, ventro-lateral recumbency, laboured/shallow respiration, rales, piloerection, ptosis and/or chromodacryorrhoea. The surviving animals had recovered f

Body weight:

Mean 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:

Isolated dark red foci were noted in the lungs of the two females found dead after exposure at 5 mg/L. One male sacrificed at 5 mg/L showed small intestines distended with gas.
No abnormalities were found at macroscopic post mortem examination of other animals at 5 mg/L and animals at 1 mg/L.

Other findings:

No information provided

The MMAD at 5 mg/L exceeded the recommended range of 1 - 4 μm, possibly due to agglomeration of aerosol particles at this high concentration. The deposition in the lungs was however sufficient considering the mortality that occurred at this concentration.

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The inhalatory LC50 value of the test substance in Wistar rats was considered to be within the range of 1.0 – 5 mg/L under the conditions of this study.

Executive summary:

The study was carried out with Wistar rats based on OECD Guidelines for Testing of Chemicals, Section 4, Health Effects. No.436, "Acute Inhalation Toxicity-Acute Toxic Class Method", September 2009. Mortality, clinical signs, body weight, gross pathology were observed.

The inhalatory LC50 value of the test substance in Wistar rats was considered to be within the range of 1-5 mg/L under the conditions of this study.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

discriminating conc.

Value:

1 000 mg/m³ air

Quality of whole database:

1 (reliable without restriction)

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited study summary, no GLP, deviations compared to OECD 402

Qualifier:

no guideline followed

Principles of method if other than guideline:

4 rabbits were dermally exposed (semi-occlusive) for 24 hours to the test substance (2000 mg/kg). Observation for mortality during 24 hours.

GLP compliance:

no

Test type:

fixed dose procedure

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2311 - 2812 grams
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
No additional data

ENVIRONMENTAL CONDITIONS
No information provided

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: the back
- % coverage:
- Type of wrap if used: gauze bandages and Saran Wrap


REMOVAL OF TEST SUBSTANCE
- Washing (if done): tepid water
- Time after start of exposure: 24 hours


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg
- Concentration (if solution): undiluted
- For solids, paste formed: no

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

2 male and 2 female per dose

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: not indicated
- Necropsy of survivors performed:
- Other examinations performed: body weight,organ weights

Statistics:

None stated

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occured.

Clinical signs:

other: No information provided

Gross pathology:

No information provided

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The LD50 was considered to be >2,000 mg/kg bw. The test substance would not be considered a toxic substance by the dermal route of administration.

Executive summary:

4 rabbits were dermally exposed (semi-occlusive) for 24 hours to the test substance (2000 mg/kg). Observation for mortality during 24 hours.

The LD50 was considered to be >2,000 mg/kg bw. The test substance would not be considered a toxic substance by the dermal route of administration.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

2 (reliable with restrictions)

Additional information

Acute oral toxicity

In the key study an acute LD50 value for rats appeared to be approximately 1430 mg/kg bw.

In a supportive study, a LD50 value of 1300 mg/kg bw in rats and 1000 mg/kg bw for guinea pigs was derived. In another limitedly reported supporting study a LD50 value of 800 -1600 mg/kg bw was reported for both rats and mice. In an acute oral toxicity study in rats with the test substance, an oral LD50 of > 2.17 ml/kg (> 2000 mg/kg) was reported.

It can be concluded that the oral LD50 of the test substance in rats is between 300 and 2000 mg/kg bw/day.

Acute inhalation toxicity

Based on an acute inhalation toxicity study in rats with the test substance, the inhalation LC50 is 1000 -5000 mg/m3. Based on two studies on sensory irritation (Babiuk 1984, Steinhagen 1983) it cannot be excluded that the test substance induces sensory irritation in rodents. The data are however not sufficient to set an effect level in humans.

Acute dermal toxicity

A dermal LD50 in rabbits of >1.25 g/kg was reported (LD50 >1250 mg/kg bw).

No mortality was noted in guinea pigs, after 24 hour dermal exposure to 5-20 cc/kg the test substance.

Both studies are of limited acceptability for the assessment of the acute dermal toxicity of the test substance and it is questionable if this study can fulfill the endpoint. Andersen (2006) published a final report on the safety assessment of the test substance. In this report it is stated that the Cosmetic Ingredient Review (CIR) Expert Panel expressed concern regarding the limited irritation data available for the test substance. Therefore, the relevance of benzoic acid data was further evaluated for this endpoint. Available data indicate that benzyl alcohol is metabolized in viable skin to benzoic acid and hippuric acid, catalyzed by alcohol dehydrogenase. This conversion of benzyl alcohol presumably involves the test substance as an intermediate and the well understood conversion of the test substance to benzoic acid, followed by conjugation with glycine to form hippuric acid. Because much of the exposure of the skin to the test substance actually will result in systemic exposure to benzoic acid it is concluded that data for benzoic acid are relevant for the systemic effects observed. The dermal LD50 of benzoic acid is set at > 2000 mg/kg.

Justification for selection of acute toxicity – oral endpoint
This study was conducted according to a method which equivalent or similar to OECD guideline 401 using rats.

Justification for selection of acute toxicity – inhalation endpoint
The study was carried out with Wistar rats based on OECD Guideline 436.

Justification for selection of acute toxicity – dermal endpoint
This study was read-across from benzoic acid. It was carried out with rabbits according to a method which is compared to OECD guideline 402.

Justification for classification or non-classification

Based on the oral LD50 values in rats of the test substance from several sources between 300 and 2000 mg/kg bw the substance is classified as Xn R22 and H302 (harmful if swallowed) according to DSD and CLP respectively.

Based on the dermal LD50 value of benzoic acid of > 2000 mg/kg, and assuming the relevance of dermal toxicity data of benzoic acid for the test substance based on the conclusion of the Cosmetic Ingredient Review Expert Panal, exposure to the test substance needs no classification for acute dermal toxicity.

Based on the inhalation LC50 value in rats of the test substance from a GLP study between 1000 and 5000 mg/m3 bw the substance is classified as Xn R20 and H332 (harmful if inhaled) according to DSD and CLP respectively.