Reaction mass of (9E)-9-Undecenal and (9Z)-9-Undecenal and undec-10-enal

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11-04-2019 to 22-05-2019

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:

2019

Report date:

2019

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:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

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

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: December 2017 ; signature: January 2018

Test type:

traditional method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(9E)-undec-9-enal; (9Z)-undec-9-enal; undec-10-enal

EC Number:

941-821-2

Molecular formula:

C11H20O

IUPAC Name:

(9E)-undec-9-enal; (9Z)-undec-9-enal; undec-10-enal

Test material form:

liquid

Details on test material:

- Physical state: Liquid
- Storage condition of test material: In a refrigerator (2-8°C) protected from light, container flushed with nitrogen
- Other: colourless

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: 9 - 10 weeks
- Weight at study initiation: Approximately the same age and body weight variation did not exceed +/- 20% of the sex mean. Females: 177-223 g and Males: 270 – 330 g
- Fasting period before study: None.
- Housing: Group housing of five animals per sex per cage in labelled polycarbonate 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 (actual 47 to 62%)
- Air changes (per hr): at least 10 (no recirculation)
- Photoperiod (hrs dark / hrs light): 12 h light / 12 h dark

IN-LIFE DATES: From: 11-04-2019 To: 22-05-2019

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

>= 2.9 - <= 3.3 µm

Geometric standard deviation (GSD):

>= 2 - <= 2.1

Remark on MMAD/GSD:

MMAD/GSD relates to:
5 mg/L (7.8 mg/L nominal), 5.1 ± 0.1 mg/L (mean achieved concentration) dose : MMAD = 3.2 GSD = 2.1 and MMAD = 3.3 GSD = 2.0
1 mg/L (2.9 mg/L nominal), 1.1 ± 0.1 mg/L (mean achieved concentration) dose : MMAD = 2.9 GSD = 2.0 and MMAD = 3.1 GSD = 2.1

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 and pressurized air. The primary aerosol was diluted with 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 23 L/min (5 mg/L exposure level) and 42 L/min (1 mg/L exposure level).
- 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: 20.7-21.2°C, 8-17% humidity.

TEST ATMOSPHERE
- Brief description of analytical method used: Actual concentration was determined (n= 19 and 14 at 5 and 1 mg/L respectively) multiple 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

VEHICLE
- Composition of vehicle (if applicable): Not applicable.
- Concentration of test material in vehicle (if applicable): Not applicable.
- Justification of choice of vehicle: Not applicable.
- Lot/batch no. (if required): Not applicable.
- Purity: Not applicable.

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.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: Not applicable.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

- 5.0 mg/L (7.8 mg/L nominal), 5.1 mg/L (mean achieved concentration) with a generation efficiency of 65%.
- 1.0 mg/L (2.9 mg/L nominal), 1.1 mg/L (mean achieved concentration) with a generation efficiency of 39%.

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: 14 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 14 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:

> 1 - <= 5 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

At 5 mg/L : all animals were found dead or humanely terminated in moribund condition within 3 hours after the 4-hours exposure.
At 1 mg/L : one male was found dead on Day 4, and one male and two females were humanely terminated in moribund condition on Day 7. No further mortality occurred.

Clinical signs:

other:

Body weight:

At 1 mg/L : body weight loss was noted for all animals, which continued until Day 4, 7 or 8 for the majority of animals which regained weight during the second week. One male showed weight loss until the end of the observation period.

Gross pathology:

At 5 mg/L : macroscopic post mortem examination revealed abnormalities of the lungs (reddish discolouration), esophagus (grey-white foamy contents) and/or thymus (many/isolated dark red or reddish foci) for eight out of ten animals that died or were humanely terminated during the study.
At 1 mg/L : macroscopic post mortem examination of the males that died or were humanely terminated during the study revealed abnormalities of the lungs (reddish discolouration), thymus (many dark red foci) or testis (reduced size left side). Macroscopic examination of the females that were terminated during the study revealed no abnormalities. Macroscopic examination of the survivors revealed lungs that were not collapsed and/or several/many reddish foci of the thymus for two males and one female. No further abnormalities were noted. Applicant assessment indicates: reduced sized of testes was seen in Male #15 only and may not be test item exposure related as was only observed in 1/5 males during the study.

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

Table 1.0 : Characteristics of the achieved atmosphere

Group Number	Nominal Concentration (mg/L)	Time-weighted mean actual concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Geometric Standard Deviation	Comments
1 (1 mg/L)	2.9	1.1 ± 0.1	2.9 – 3.1	2.0 – 2.1	n=14 samples ; generation efficiency (ratio of actual and nominal concentration) of 39%
2 (5 mg/L)	7.8	5.1 ± 0.1	3.2 – 3.3	2.0 – 2.1	n=19 samples ; generation efficiency (ratio of actual and nominal concentration) of 65%

 

Table 2.0 : Mortality data

Group Number	Nominal Concentration (mg/L)	Time-weighted mean actual concentration (mg/L)	Mortalities
			Female	Male
1	2.9	1.1 ± 0.1	2/5	2/5
2	7.8	5.1 ± 0.1	5/5	5/5

Clinical signs:

At 5 mg/L : slow breathing, shallow breathing, difficult breathing and gasping was seen for during exposure. After exposure, lethargy, flat and/or hunched posture, laboured respiration and ptosis were seen for the animals prior to mortality.

At 1 mg/L : slow breathing was seen during exposure. After exposure, lethargy, hunched posture, slow breathing and/or laboured respiration, were seen for the animals on Days 1 and/or 2. There was reoccurrence of the signs in one female and one male humanely terminated on Day 7. For one surviving male and one surviving female from Day 7 onwards, in addition quick breathing, rales and/or piloerection were noted. The survivors had recovered from clinical signs by Day 13 or 14.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

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 > 1 and ≤ 5 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 fourteen day observation period. The time-weighted mean achieved atmosphere concentrations were as follows: 5.1 ± 0.1 mg/L based on a nominal concentration of 7.8 mg/L and/or1.1 ± 0.1 mg/Lbased on a nominal concentration of 2.9 mg/L. The atmosphere generation efficiencies were 65% and 39%, respectively. The characteristics of the achieved atmosphere where Mean Mass Median Diameter (particle size): > 2.9 μm and < 3.3 μm with geometric Standard Deviation > 2.0 and < 2.1. At 5 mg/L, all animals were found dead or humanely terminated in moribund condition within 3 hours after the 4-hours exposure. At 1 mg/L, one male was found dead on Day 4, and one male and two females were sacrificed in moribund condition on Day 7. No further mortality occurred. At 5 mg/L, slow breathing, shallow breathing, difficult breathing and gasping was seen during exposure. After exposure, lethargy, flat and/or hunched posture, laboured respiration and ptosis were seen prior to mortality. At 1 mg/L, slow breathing was seen for all males/females during exposure. After exposure, lethargy, hunched posture, slow breathing and/or laboured respiration, were seen on Days 1 and/or 2. There was reoccurrence of the signs in one female and one male humanely terminated on Day 7. For one surviving male and one surviving female from Day 7 onwards, in addition quick breathing, rales and/or piloerection were noted. The survivors had recovered from the clinical signs by Day 13 or 14. Body weight loss was noted for all males/females, at 1 mg/L, which continued until Day 4, 7 or 8 for the majority which regained weight during the second week. One male showed weight loss until the end of the observation period. At 5 mg/L, macroscopic post mortem examination revealed abnormalities of the lungs (reddish discolouration), esophagus (grey-white foamy contents) and/or thymus (many/isolated dark red or reddish foci) for eight out of ten male/females in mortality or were humanely terminated in moribund condition during the study. At 1 mg/L, macroscopic post mortem examination of the males in mortality or were humanely terminated during the study revealed abnormalities of the lungs (reddish discolouration), thymus (many dark red foci) or testis (reduced size left side, isolated to one male). Macroscopic examination of the females that were sacrificed in moribund condition during the study revealed no abnormalities. Macroscopic examination of the surviving animals revealed not collapsed lungs and/or several/many reddish foci of the thymus for two males and one female. No further abnormalities were noted. Under the conditions of this study, the inhalation 4h-LC50 (male/female) was considered to be > 1 and ≤ 5 mg/L within the Wistar: Crl:WI(Han) rat.