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Toxicological information

Repeated dose toxicity: inhalation

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Administrative data

Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
2011-06-01 to 2011-06-21
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study; GLP study without deviations

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)
Version / remarks:
2009
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
CAS name: 1,4-Cyclohexanedicarboxamide, N1,N1,N4,N4-tetrakis(2-hydroxyethyl)-, trans
Chemical characterization: Trans-N,N,N',N'-Tetrakis(2-hydroxyethyl)-cyclohexyl-1,4-diamide
Characteristics: Whitish, solid, powder, hydroscopic
Batch: 715-5
Contents:
91.53 % Trans-N,N,N',N'-Tetrakis(2-hydroxyethyl)-cyclohexyl-1,4-diamide

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
- Source: Charles River Laboratories, Sulzfeld (Germany)
- Strain: rats, F344, SPF
- Age: approx. 7 weeks when supplied
- Animals: 20 males, 20 femals
- Acclimatisation: at least 5 days
- Weight at study initiation: male: 198.8g - 201.0g, female: 140.0g - 142.0g
- Diet: ad libitum, ssniff R/M-H V 1534-300
- Water: tap water ad libitum
- Temperature (°C): 20.8 - 22.3 °C, mean: 21.4 °C
- Humidity: about 37 - 77 %, mean 61.7 &
- Illumination: 12 hours artifical fluorescent light and 12 hours dark
- Air exchange: 12 per hour

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose/head only
Vehicle:
other: conditioned air
Remarks on MMAD:
MMAD / GSD: The mass median aerodynamic diameter of the dust particles was 3.13, 3.20 and 3.55 µm for the low, mid and high concentration. This is slightly higher than the recommended range of 1 to 3 µm. But although the test substance was ground before producing the dust and a separator for larger particles was used, a smaller aerodynamic diameter was not obtainable.
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: see attachment, Head Nose Only Exposure Unit from TSE-Systems GmbH, Bad Homburg, Germany
- Method of holding animals in test chamber:
- Source and rate of air:
- Method of conditioning air:
- System of generating particulates/aerosols: test substance is milled in a ball mill and pressed to a dust cake. In the dust generator a scrapper
removes parts of this cake. The dust is removed from the scrapper and dispersed by the flow inside the outlet nozzle into the inhalation unit.
The mass median aerodynamic diameter (MMAD) of the dust in the breathing zone shall be in the range of 1 to 3 µm with a geometric standard
deviation of 1.5 to 3.0. A slightly increased MMAD will be accepted as otherwise the desired dust concentration cannot be produced.
- Temperature, humidity in air chamber: 18.9 - 20.9 °C, humidity: lower than 5%,
- Air flow rate:
- Air change rate:
- Method of particle size determination: cascade impactor (Berner-Impaktor Type LPI4/0,06/2 from Hauke KG, Gmunden, Austria).
- Treatment of exhaust air:

TEST ATMOSPHERE
- Analyses of dust particleize: three times during study
- Graimetric analyses of dust concentration: three times per day


Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The dust concentration in the breathing zone was determined gravimetrically. An accurately measured volume of air from the inhalation devices was sucked through a pre-weighed filter with cotton wool. The filters were dried before and after the sampling by pressing dry air through them. From the weight difference and the volume the actual dust concentration was calculated.
Duration of treatment / exposure:
5 days per week for 2 weeks
Frequency of treatment:
5 days/week x 6 hours/day
Doses / concentrations
Remarks:
Doses / Concentrations:
0.12, 0.36, 1.03 mg/l
Basis:
analytical conc.
No. of animals per sex per dose:
5
20 males and 20 females
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Based on the technical possibilities of the dust generation and the absence of toxic actions at one preliminary exposure.
In preliminary experiments the highest dust concentration which could be produced with acceptable particle size distribution was 1.1 mg/L. One
animal was exposed to this dust concentration for 6 hours and showed no noteworthy signs of toxicity. Therefore this concentration was the target
for the high concentration group. The low concentration was 1/10 of the high one and the mid concentration was the geometric mean.
Positive control:
not nesessary

Examinations

Observations and examinations performed and frequency:
Animal observations: All animals, before and after the exposure, on days without exposure once a day.
Body weights: All animals, twice per week.
Feed consumption: All animals, for weekly periods.
Sacrifice and pathology:
Necropsy with gross pathological examination: All animals on Day 15.
Organ weight determination: All animals, fresh weights of lungs, kidneys, livers and spleens, at necropsy.
Histopathological examination: As no significant effects of the test substance exposure was seen, no histopathological examinations were performed.
Other examinations:
no other examinations
Statistics:
- Analysis of variance followed by the Scheffé-test: all data with means and standard deviations determined, comparison of more than two groups
t-test
- t-test: all data with means and standard deviations determined, for comparison of two groups only
- H-test of Kruskal and Wallis followed by the test of Nemenyi: counted events with scoring or in cases where the requirements for the analysis of
variance were not fulfilled
- Chi2-test: counted events
- Fisher's exact test: counted events, if the Chi2-Test was not applicable

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Description (incidence and severity):
Chromodacryorrhea occurred in animals of all groups during the inhalation exposure. It was probably caused by the restraining in the inhalation tubes.
Mortality:
no mortality observed
Description (incidence):
Chromodacryorrhea occurred in animals of all groups during the inhalation exposure. It was probably caused by the restraining in the inhalation tubes.
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
no effects observed
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Details on results:
- Mortality: There was no mortality prior to scheduled sacrifice.
- Observations in life: Chromodacryorrhea occurred in animals of all groups during the inhalation exposure. It was probably caused by the
restraining in the inhalation tubes.
- Body weights and feed consumption: The body weights, weight gains, and feed consumptions were similar in all groups. There was no significant
difference between the control and any dosed group.
- Necropsy with gross pathological examination: There were no spontaneous findings made at the gross examination during the necropsy in any of the animals.
- Organ weights: There were no significant differences in the organ weights or the organ weight / body weight ratios between the control group and
any of the dosed groups.

Effect levels

Dose descriptor:
NOEL
Effect level:
> 1.03 mg/L air
Sex:
male/female

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

no remarks

Applicant's summary and conclusion

Conclusions:
The No-observed-effect-level (NOEL) of trans-N1,N1,N4,N4-Tetrakis(2-hydroxyethyl)1,4-cyclohexanedicarboxamide dust was therefore larger than 1.03 mg/L.
Executive summary:

This study was performed to evaluate the toxicity of trans-N1,N1,N4,N4-Tetrakis(2-hydroxyethyl)1,4-cyclohexanedicarboxamide after a repeated administration per inhalation to rats, according to OECD-Guideline 412/413, 7 September 2009, as far as useful for a dose range finder study.

The used dust concentration of the high dose group, 1.03 mg/L, was the highest technically feasible dust concentration. Nevertheless no toxic effect was observed in this study after a two week exposure to this dust. The body weight, the feed consumption, the behaviour, and selected organ weights were not changed in the exposed groups.

The No-observed-effect-level (NOEL) of trans-N1,N1,N4,N4-Tetrakis(2-hydroxyethyl)1,4-cyclohexanedicarboxamide dust was therefore larger than 1.03 mg/L for rats after repeated exposure via inhalation for two weeks.

.