(2E)-2-methyl-3-(4-methylphenyl)prop-2-en-1-ol

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21-05-2013 to 04-06-2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

Justification for type of information:

Information as to the availability of the in vivo study is provided in 'attached justification'.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nohsan, Notification No 8147, April 2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected: March 2013 ; signature: May 2013

Test type:

traditional method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(2E)-2-methyl-3-(4-methylphenyl)prop-2-en-1-ol

EC Number:

700-548-7

Cas Number:

56138-10-4

Molecular formula:

C11H14O

IUPAC Name:

(2E)-2-methyl-3-(4-methylphenyl)prop-2-en-1-ol

Details on test material:

- Physical state: Waxy solid at temperature < 23°C and liquid at temperature > 23°C
- Storage condition of test material: In refrigerator (2-8°C) in the dark under nitrogen
- Other: white waxy solid at temperature < 23°C and clear colourless liquid at temperature > 23°C

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Recognised supplier
- Age at study initiation: 10 - 11 weeks
- Weight at study initiation: Approximately the same age and body weight variation did not exceed +/- 20% of the sex mean. Females: 194-224 g and Males: 310 – 325 g
- Fasting period before study: None.
- Housing: Group housing of five animals per sex per cage in labelled Makrolon cages (type IV), containing sterilised sawdust bedding and paper cage enrichment.
- Diet (e.g. ad libitum): Certified diet from recognised supplier, provided ad libitum (except for exposure period period)
- Water (e.g. ad libitum): mains drinking water, ad libitum (except for exposure period period)
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 24
- Humidity (%): 40 to 70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 h light / 12 h dark

IN-LIFE DATES: From: 21-05-2013 To: 04-06-2013

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

>= 3.3 - <= 3.4 µm

Geometric standard deviation (GSD):

>= 1.9 - <= 2

Remark on MMAD/GSD:

MMAD/GSD relates to: 6.9 mg/L (nominal), 5.1 ± 0.1 mg/L (mean achieved concentration) dose - determined twice during the study

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: An aerosol was generated by nebulization of the test substance by means of a nebulizer (type 950) and pressurized air. The nebulizer was placed in a water bath of approximately 40 ºC which was placed on a magnetic stirrer. The primary aerosol was diluted with humidified pressurized air before it entered the exposure chamber
- Exposure chamber volume: Not reported. Was consistent with Am. Ind. Hyg Assoc. J. 44(12): 923-928, 1983.
- Method of holding animals in test chamber: Restraining tubes.
- Source and rate of air: filtered air
- Method of conditioning air: Compressed air was supplied by means of an oil free compressor and passed through a water trap and respiratory quality filters before it was introduced to the nebulizer.
- System of generating particulates/aerosols: nebulizer; the chamber mean total flow rate was maintained at 18 L/min.
- Method of particle size determination: Particle size was determined using a cascade impactor. The device consisted of eight impactors stages containing fiber glass filters.
- 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, in air chamber: The temperature and relative humidity inside the exposure chamber were measured by an electronic thermometer/humidity meter: 27.6-29.1°C, 87-91% humidity.

TEST ATMOSPHERE
- Brief description of analytical method used: Actual concentration was determined sixteen times during the exposure period. Samples were 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 collected amount of the test substance in the air sample was
measured gravimetrically. Sample volumes were measured by means of a dry gas meter. The time-weighted mean concentration with the standard deviation was calculated. Full details of the analytical method are provided in the full study report.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: The particle size of the generated atmosphere inside the exposure chamber was determined two times during each exposure period using a cascade impactor. The particle size distribution for each group is reported in table 1.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The Mass Median Aerodynamic Diameter (MMAD) was determined and is reported for each group in table 1.
stribution for each group is reported in table 1.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

6.9 mg/L (nominal), 5.1 mg/L (mean achieved concentration) with a generation efficiency of 74%.

No. of animals per sex per dose:

5 per sex per dose. Full details are provided in table 2.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 15 days
- Frequency of observations and weighing: Mortality, twice daily. Clinical signs three times during exposure and on day one at one and three hours and then once daily. Any evidence of mortality or overt toxicity was recorded at each observation. Individual body weights were recorded on arrival, prior to treatment on the day of exposure and on Days 1, 4, 8 and 15 or after mortality.
- Necropsy of survivors performed: yes (and in the event of any mortalities)
- Other examinations performed: clinical signs, body weight, organ weights, and any other relevant toxicological effects were reported.

Statistics:

No statistical analysis was performed.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.1 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

1 female mortality occurred on day 1 ; mortalities are reported in table 3.

Clinical signs:

other: No clinical signs were noted during exposure. After exposure, the clinical signs observed among the animals were lethargy, tremors, flat posture, hunched posture, uncoordinated movements, slow breathing, laboured respiration, shallow respiration, rales, g

Body weight:

All animals exhibited body weight losses on the first week post-exposure. Body weight gains were noted in all surviving animals during the remainder of the recovery period.

Gross pathology:

In the female mortality: macroscopic post mortem examination of the female found dead revealed light red discoloration of the lungs.
In the survivors: cloudy eyes were observed. No other abnormalities were found at macroscopic examination.

Other findings:

- Other observations: The respiratory tract was subjected to a detailed macroscopic examination for signs of irritancy or local toxicity during necropsy.

Any other information on results incl. tables

Additional comments regarding test atmosphere generation:

It is noted within the study that the time-weighted mean actual concentration was 5.1 ± 0.1 mg/L and that the generation efficiency was 74%. The concentration measurements equally distributed over time demonstrated that the atmosphere was sufficiently stable at the mean total airflow of 18 L/min. Full details are available within the full study report.

 

Table 1. Characteristics of the achieved atmosphere:

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Geometric Standard Deviation	Comments
1	5.1	> 3.3 - < 3.4	> 1.9 - < 2.0	MMAD of 10% of atmosphere was < 0.5 µm

 

Table 2. Mean achieved atmosphere concentrations:

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Standard Deviation	Nominal (mg/L)
1	5.1	0.115	6.9

 

Table 3. Mortality data summary:

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Mortalities
		Female	Male	Total
1	5.1	1/5	0/5	1/10

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the study, the inhalation 4h-LC50 (male/female) was considered to be > 5.1 mg/L within the Crl:WI(Han) rat.

Executive summary:

The study was performed according to OECD TG 403, EU Method B.2, US EPA OPPTS 870.1300 and Japanese JMAFF guidelines in accordance with GLP to assess the acute inhalation toxicity of the test item. A single group of ten Wistar: Crl:WI(Han) strain rats (five males and five females) were exposed to an aerosol atmosphere of the test item. The groups were exposed for four hours using a nose only exposure system, followed by a fifteen day observation period. The mean achieved atmosphere concentrations were as follows: 5.1 ± 0.1 mg/L based on a nominal concentration of 6.9 mg/L. The characteristics of the achieved atmosphere where Mean Mass Median Diameter (particle size): > 3.3 μm and < 3.4 μm with geometric Standard Deviation > 1.9 and < 2.0. There was no male and one female mortalities in the 5.1 mg/L mean achieved atmosphere concentration. The single female mortality occurred within 4 hours post-exposure.No clinical signs were noted during exposure. After exposure, the clinical signs observed among the animals were lethargy, tremors, flat posture, hunched posture, uncoordinated movements, slow breathing, laboured respiration, shallow respiration, rales, gasping, piloerection, chromodacryorrhoea and/or ptosis. The surviving animals had recovered from the signs between Days 5 and 6, except for the rales in one male that were also present on Day 8. Body weight loss was noted in all animals during the first week post-exposure. All animals regained weight during the second week. Macroscopic post mortem examination of the female found dead revealed light red discoloration of the lungs. Cloudy eyes were seen in two surviving males. No other abnormalities were found at macroscopic examination. Under the conditions of this study, the inhalation 4h-LC50 (male/female) was considered to be > 5.1 mg/L within the Wistar: Crl:WI(Han) rat.