Polyamide wax

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2000-03-15 to 2001-01-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK
- Age at study initiation: 7 and 8 weeks
- Weight at study initiation: 257 to 281g (Males) and 213 to 240g (females)
- Fasting period before study: no
- Housing: housed by sex, in groups of 5, in cages made of stainless steel sheet and wire mesh
- Diet (e.g. ad libitum): SDS rat and mouse diet ad libitum
- Water (e.g. ad libitum): water ad libitum
- Acclimation period: 8 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): max: 22.5°C, min: 21.5°C
- Humidity (%): max: 60%, min: 34%
- Air changes (per hr): at least 15 air changes per hour
- Photoperiod (hrs dark / hrs light): artificial light between 06:00 and 18:00 GMT daily

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: flow through nose only chamber. This system was an aluminium alloy cylinder with a volume of approximately 30 liters. The conditioned test atmosphere entered through a port at the top centre of the chamber and passed out through a port at the base section below the level of the rats.
- Method of holding animals in test chamber: Rats were held in polycarbonate tubes with their snouts protruding from the end of the tubes into the exposure chamber.
- Source and rate of air: A supply of clean, dry, neutralised air was connected to the generator and the supply pressure was adjusted to give a flow
rate of 20l/min.
- System of generating particulates/aerosols: Wright Dust Feed mechanism designed to produce and maintain atmospheres of dust by suspending material scraped from the surface of a compressed powder in a stream of dry air. The concentrations of dust were altered by changing the gear ratio (and therefore the speed of rotation of the compressed powder towards the scraper blade) of the mechanism.The output of the WDF was connected to the top inlet port of the chamber via the elutriation column which reduced by sedimentation the amount of non respirable particulate in the test atmosphere.
- Temperature, humidity, pressure in air chamber: Temperature was measured using an alcohol-in-glass thermometer and relative humidity was measured with an infrared water vapour analyser. The temperature and relative humidity were recorded at the start of exposure and then at 30-minute intervals during the 4-hour exposure. The mean chamber temperatures were within expected ranges (20.5 and 20.4 °C for controls and test group) as well as the relative humidity (32 and 34 °C for controls and test group). Pressure in air chamber was not reported.
- Method of particle size determination: Particle size analysis of generated atmospheres was performed using a 8-stage cascade impactor (Marple 298). Samples were collected twice during exposure (86 and 210 min). Samples were also collected from a vacant animal exposure port (animals breathing zone). The collection substrates and the backup filter were weighed before and after sampling and the weight of test item, collected at each stage, was calculated by this difference. The total amount collected for each stage was used to determine the cumulative amount below each cut-off point size. In this way, the proportion (%) of aerosol less than < 0.52, 0.93, 1.55, 3.50, 6.0, 9.80, 14.80 and 21.30 µm (aerodynamic diameter) was calculated. From this data, the Mass Median Aerodynamic Diameter (MMAD), and Geometric Standard Deviation (GSD) were calculated. The mean MMAD was 5.5 µm and the geometric standard deviation (GSD) was 1.99. The Mass Median Aerodynamic Diameter was slightly above the targeted range of 1 to 4 µm, it came from the characteristics of the test item and the possible formation of aggregates during the aerosol generation.
- Treatment of exhaust air: The exhaust airflow was calibrated and adjusted to produce a slightly negative pressure.

TEST ATMOSPHERE
- Brief description of analytical method used: A measured volume of air was drawn at a rate of 2 litres/minute from an unused exposure
port on the exposure chamber through a glass microfibre filter, mounted in an open face filter holder and measured using a wet-type gas meter. Five samples were collected at approximately hourly intervals after equilibration during the exposure. The filters were weighed before and after sampling.The difference in the pre- and post-sampling weights, divided by the volume of atmosphere sampled, was equal to the actual achieved test atmosphere concentration. The mean achieved test atmosphere concentration was 4.06 +/- 0.214 mg/L: it was the maximum practicable concentration.
- Samples taken from breathing zone: yes

VEHICLE
- none

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

<= 4 h

Concentrations:

Mean achieved atmosphere concentration: 4.06 mg/L ; Standard deviation: 0.214
This concentration was the maximum practicable.

No. of animals per sex per dose:

5/sex

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: intermittently f observed for signs of reaction to the test substance during exposure and at least twice daily throughout
the observation period. the clinical signs were recorded at the end of the chamber equilibration period, at 0.25, 0.5 and 1 hours then hourly intervals during the exposure, immediately after exposure and then at 1.0 and 2.0 hours after exposure.
- Frequency of weighing: at least twice during the week prior to exposure, immediately before exposure and weekly during the observation period.
- Necropsy of survivors performed: yes, at the end of the 14-day observation period, the rats were killed by intraperitoneal injection of pentobarbitone sodium and exsanguinated when clinically dead. All rats were subjected to a deatailed macroscopic examination.

Statistics:

None

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 4.06 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: maximum practicable concentration

Mortality:

There were no unscheduled deaths.

Clinical signs:

other: - During exposure: > Exaggerated breathing was evident in all treated rats from 30 minutes into exposure. Soiling of the fur with excreta was observed in all treated and control animals from 30 minutes and 1 hour during the exposure respectively and w

Body weight:

The mean bodyweight gains for treated rats were less than controls during the first week following exposure. Thereafter, the mean bodyweight gain
of female and male treated rats was similar to and less than the control values respectively.
There were no treatment-related effects on food consumption.

Gross pathology:

There were no treatment-related findings at the macroscopic examination .
There were no treatment-related effects on lungs weight.

Any other information on results incl. tables

Table 7.2.2/1: Body weights - individual and group mean values (g)

Group	Rat	Day of observation
		-6	-3	0	7	14
1M (control)	1	213	241	263	322	351
	2	213	240	257	304	330
	3	225	258	281	333	356
	4	224	254	277	325	367
	5	215	249	271	318	355
	Mean	218	248	270	320	352
2M (treated)	11	213	244	272	310	343
	12	221	248	264	298	328
	13	212	244	265	308	346
	14	216	240	266	294	323
	15	216	239	259	291	316
	Mean	216	243	265	300	331
1F (control)	6	200	217	227	325	247
	7	201	206	218	225	241
	8	199	210	212	225	239
	9	203	216	215	231	251
	10	209	222	231	240	262
	Mean	202	214	221	231	248
2F (treated)	16	205	209	213	219	224
	17	204	219	223	230	252
	18	202	206	217	229	242
	19	203	210	231	235	241
	20	204	214	217	218	231
	Mean	204	212	220	226	238

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No death occurred at the concentration of 4.06 mg/L which is the maximum practical atmosphere concentration.
Therefore, the substance is not classified according to Regulation (EC) No. 1272/2008 and its subsequent amendments on classification, labeling and packaging (CLP) of substances and mixtures.

Executive summary:

The substance was tested for acute inhalation toxicity study according to OECD 403 guideline and in compliance with Good Laboratory Practice. One treated and one control group, each of five male and five female Sprague-Dawley rats were exposed by nose-only inhalation to the test substance for 4 hours at a concentration of 4.06 mg/l or air respectively. The concentration of 4.06 mg/l was the maximal practical atmosphere concentration.

Each animal was observed for mortality and clinical signs at hourly intervals during exposure, then one hour and two hours after exposure and at least twice a day during the 14-day observation period. Bodyweights were recorded before treatment then on day of exposure and weekly during the observation period. All surviving animals were necropsied at the end of the observation period.

No mortality occurred during the study. Clinical signs as exaggerated breathing was evident for all treated animals from 30 minutes during the exposure and immediatly post exposure, persisting for most animals to day 4. Gasping and noisy breathing were noted for some animals post-exposure, the latter sign persisting in 1 male to Day 4. The mean bodyweight gain for treated rats was less than controls during the first week following exposure. Thereafter, the mean bodyweight gain of female and male treated rats was similar to and less than control values respectively. There were no treatment-related findings at the macroscopic examination.

The 4 -hour inhalation LC50 was found to be greater than 4.06 mg/l (ie 4060 mg/m3).