N-[3-(dimethylamino)propyl]stearamide monoacetate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2015-03-09 To 2015-07-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-[3-(dimethylamino)propyl]stearamide monoacetate

EC Number:

236-291-8

EC Name:

N-[3-(dimethylamino)propyl]stearamide monoacetate

Cas Number:

13282-70-7

Molecular formula:

C23H48N2O.C2H4O2

IUPAC Name:

N-[3-(dimethylamino)propyl]stearamide monoacetate

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Remarks:

CRL

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Rationale for alternative/additional species to rat (if applicable): n/a
- Source: Charles River Laboratories International, Inc., Raleigh, North Carolina, U.S.A.
- Females (if applicable) nulliparous and non-pregnant: [yes]
- Rationale for use of males (if applicable):n/a
- Age at study initiation: 7 weeks old.
- Weight at study initiation: Male between 371 and 395 grams; Females 231 and 268 grams at the time of exposure.
- Fasting period before study:n/a
- Housing:housed individually in solid bottom caging with bedding and enrichment.
- Historical data:n/a
- Diet (e.g. ad libitum): PMI® Nutrition International, LLC Certified Rodent LabDiet® 5002, ad libitum.
- Water (e.g. ad libitum):tap water were available ad libitum.
- Acclimation period:6 days prior testing.
- Microbiological status when known: Water samples are analyzed for total bacterial counts, and the presence of coliforms, lead, and other contaminants. Samples from freshly washed cages and cage racks are analyzed to ensure adequate sanitation by the cagewashers.
- Method of randomisation in assigning animals to test and control groups: n/a

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-26°C
- Humidity (%): 30-70%
- Air changes (per hr): 28 air changes per hour.
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle.


IN-LIFE DATES: From: 9 March 2015 To: 23 March 2015

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

water

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:Spraying Systems Company® nebulizer
- Exposure chamber volume: 34 L.
- Method of holding animals in test chamber:restrained in perforated stainless steel cylinders with conical nose pieces. The restrainers were inserted into a polymethylmethacrylate faceplate attached to the exposure chamber so that the nose of each animal extended into the exposure chamber.
- Source and rate of air (airflow):
- Method of conditioning air:
- System of generating particulates/aerosols:
- Method of particle size determination:
- Treatment of exhaust air:
- Temperature, humidity, pressure in air chamber:

TEST ATMOSPHERE
- Brief description of analytical method and equipment used: The test substance was metered into the nebulizer with a Cole-Palmer Masterflex® console drive pump. High-pressure air, metered into the nebulizer by a Brooks model 5850E mass flow controller, carried the resulting atmosphere into the exposure chamber. Chamber concentrations of test substance were controlled by varying the test substance feed rate to the nebulizer.
The test atmosphere was exhausted through a high-capacity particle filter cartridge prior to discharge into the fume hood.
- Samples taken from breathing zone: yes
- Time needed for equilibrium of exposure concentration before animal exposure:

VEHICLE
- Composition of vehicle (if applicable): test material diluted 10 times by volume within distilled water.
- Concentration of test material in vehicle (if applicable): 5 mg/L
- Justification of choice of vehicle: n/a
- Lot/batch no. (if required): n/a
- Purity: n/a

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution:Samples to determine aerosol size distribution (mass median aerodynamic diameter, geometric standard deviation, and percent percent aerosols less than 1, 3, and 10 μm diameter.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMAD (GSD) were 4.1 μm (2.5), 3.0 μm (2.5), and 3.9 μm (2.4) which are regarded as respirable.

Duration of exposure:

4 h

Concentrations:

maximum practically-attainable atmospheric concentration of 4.0 ± 0.30 mg/L (diluted)

No. of animals per sex per dose:

one group of 5 male and 5 female (nulliparous and non-pregnant)

Details on study design:

- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing:
- Necropsy of survivors performed: yes/no
- Clinical signs including body weight : yes.
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:

Statistics:

Upon completion of the exposures, CITADS sample results were transferred to the Camile Inhalation Reporting and Analysis System (CIRAS), which collated sample calculations.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4 mg/L air

Based on:

test mat. (dissolved fraction)

Remarks:

diluted

Exp. duration:

4 h

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

All animals survived the 4-hour exposure to 4.0 mg/L (diluted) H-31339 but 2 (of 5) male rats and 1 female rat died during the 14-day recovery period. The fractional mortalities were 2/5 for male rats and 1/5 for female rats.

Clinical signs:

bodyweight loss

Body weight:

- greater than 10% body weight loss: n/a
- lower than 10% body weight loss:maximum lost 13% .
- other body weight observations:
Five (of 5) male rats lost 6.6-13% of their body weights on test day 2. One male was later found dead on the same day and another male was found dead on day 3. One of the 3 surviving males lost 7.7 and 1.7% of his body weight on test day 3 and 4, respectively. Three (of 5) female rats lost 12-13 % of their body weights on test day 2 and one of them was later found dead on the same day. Two of the 4 surviving females lost <7% of their body weights on test day 3 and only 1 female lost 4.1% on test day 4. The weight variation in animals used on an exposure did not exceed ± 20% of the mean weight of each sex.
All other animals gain weights and no abnormalities were detected during the rest of the 14-day recovery period.

Gross pathology:

Gross findings were present in 3 male and 4 female rats administered 4.0 mg/L of diluted test substance: 2 found dead males, 1 found dead female and the remainder at scheduled sacrifice. Five of these animals (2 males and 3 females) had multifocal to diffuse dark discoloration of the lung, often concentrating in the cranial portion of the lung. One found dead male additionally had expanded lungs and cloudy discoloration of the left eye. The two found dead males had red staining on their faces, and the found dead female had thick, tan discoloration in the trachea. The observations are presumed related to test substance exposure. No other gross findings were observed.

Any other information on results incl. tables

Mortality

 

Sex	Mean Atmospheric Concentration (mg/L)	Mortality (deaths/exposed)
Male	4.0	2/5
Female	4.0	1/5

 

Summary of Clinical Observations and Mortality in Male Rats

 

Found dead
Number of Observations	2
Number of Animals	2
Days from – to	2  3
Scheduled sacrifice
Number of Observations	3
Number of Animals	3
Days from – to	15  15
Breathing - laboured
Number of Observations	8
Number of Animals	3
Days from – to	1  4
Breathing – lung noise
Number of Observations	3
Number of Animals	1
Days from – to	2  4
Breathing - slow
Number of Observations	1
Number of Animals	1
Days from – to	2  2
Discharge - red
Number of Observations	10
Number of Animals	5
Days from – to	1  4
Gasping
Number of Observations	6
Number of Animals	3
Days from – to	1  4
Discoloured fur - yellow
Number of Observations	1
Number of Animals	1
Days from – to	2  2

 

Summary of Clinical Observations and Mortality in Female Rats

 

 

Found dead
Number of Observations	1
Number of Animals	1
Days from – to	2  2
Scheduled sacrifice
Number of Observations	4
Number of Animals	4
Days from – to	15  15
Breathing – laboured
Number of Observations	7
Number of Animals	3
Days from – to	1  4
Breathing – lung noise
Number of Observations	1
Number of Animals	1
Days from – to	4  4
Discharge - red
Number of Observations	9
Number of Animals	5
Days from – to	1  4
Gasping
Number of Observations	7
Number of Animals	3
Days from – to	1  4
Discoloured fur – yellow
Number of Observations	5
Number of Animals	2
Days from – to	2  4

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

While an exposure atmosphere of ≥ 5 mg/L could not be obtained due to the waxy property of the test substance, 4.0 mg/L H-31339 was the highest feasible airborne concentration that could be achieved and required a 10X dilution of the test substance with distilled water.
Under the conditions of this study, the 4-hour inhalation median lethal concentration (LC50) for (diluted) H-31339 in male and female rats was > 4.0 mg/L, the maximum practically-attainable atmopheric concentration, and > 0.66 mg/L solids aerosol concentration.

Executive summary:

The objective of this study was to evaluate the acute inhalation toxicity of H-31339 when administered as an aerosol for a single, 4-hour, nose-only exposure to one group of 5 male and
5 female (nulliparous and non-pregnant) Crl:CD(SD) rats. H-31339 used for this study was a white solid with a purity of 96% by analysis. Due to the waxy property, the test substance was diluted 10 times (by volume) with distilled water to facilitate the generation of an aerosol exposure atmosphere. The test atmosphere was generated by aerosolization of H-31339 in air using a nebulizer and the airborne concentration of H-31339 was determined by gravimetric analysis. During a 14-day recovery period, all animals were weighed and observed for mortality and clinical signs of toxicity. A gross pathological examination was performed on all animals at the scheduled necropsy or shortly after they were found dead.

During the exposure, rats were exposed to a maximum practically-attainable atmospheric concentration of 4.0 ± 0.30 mg/L (diluted) H-31339 (mean ± standard deviation) as determined by gravimetric analysis of wet filters. The solids aerosol concentration of the same atmosphere, determined by desiccated filter weights, was 0.66 ± 0.030 mg/L. The mass median aerodynamic diameter and geometric standard deviation, MMAD (GSD), was determined 3 times for the atmosphere and measured 4.1 μm (2.5), 3.0 μm (2.5), and 3.9 μm (2.4).

All animals survived the 4-hour exposure to 4.0 mg/L (diluted) H-31339 but 2 (of 5) male rats and 1 female rat died during the 14-day recovery period. The fractional mortalities were 2/5 for male rats and 1/5 for female rats.

All animals displayed normal startle response during the exposure (test day 1), and no abnormalities were observed. Clinical signs of toxicities including labored breathing, slow breathing, lung noise, gasping, and/or discolored fur were observed in 3 male and 4 female rats during test days 1-4. Five (of 5) male rats lost 6.6-13% of their body weights on test day 2. One male was later found dead on the same day and another male was found dead on day 3. One of the 3 surviving males lost 7.7 and 1.7% of his body weight on test day 3 and 4, respectively. Three (of 5) female rats lost 12-13 % of their body weights on test day 2 and one of them was later found dead on the same day. Two of the 4 surviving females lost <7% of their body weights on test day 3 and only 1 female lost 4.1% on test day 4. All other animals gain weights and no abnormalities were detected during the rest of the 14-day recovery period.

Gross findings were present in 3 male and 4 female rats administered 4.0 mg/L of diluted test substance: 2 found dead males, 1 found dead female and the remainder at scheduled sacrifice. Five of these animals (2 males and 3 females) had multifocal to diffuse dark discoloration of the lung, often concentrating in the cranial portion of the lung. One found dead male additionally had expanded lungs and cloudy discoloration of the left eye. The two found dead males had red staining on their faces, and the found dead female had thick, tan discoloration in the trachea. The observations are presumed related to test substance exposure. No other gross findings were observed.

While an exposure atmosphere of ≥ 5 mg/L could not be obtained due to the waxy property of the test substance, 4.0 mg/L H-31339 was the highest feasible airborne concentration that could be achieved and required a 10X dilution of the test substance with distilled water.

Under the conditions of this study, the 4-hour inhalation median lethal concentration (LC50) for (diluted) H-31339 in male and female rats was > 4.0 mg/L, the maximum practically-attainable atmopheric concentration, and > 0.66 mg/L solids aerosol concentration.