Glutaral

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed in the seventies i.e. prior to guideline implementation and GLP requirements. The study was considered to be scientifically acceptable. The main informations also were reported in a review published 1986 by Ballantyne B and were published as abstract.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Reference 2

Reference Type:

publication

Title:

Subchronic inhalation toxicity of glutaraldehyde

Author:

Ballantyne B, Greenspan BJ, Fowler EH, Snellings WM

Year:

1985

Bibliographic source:

The Toxicologist 5: 29, Abstract 115

Reference 3

Reference Type:

review article or handbook

Title:

Unnamed

Year:

1986

Materials and methods

Principles of method if other than guideline:

The study was conducted according to specific protocol and amendments to protocol of the Chemical Hygiene Fellowship (1979)

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Glutaral

EC Number:

203-856-5

EC Name:

Glutaral

Cas Number:

111-30-8

Molecular formula:

C5H8O2

IUPAC Name:

glutaraldehyde

Test material form:

liquid

Specific details on test material used for the study:

- Name of test material (as cited in study report): Glutaraldehyde 50% aq. solution
- Supplier: Union Carbide Corporation
- Physical state: liquid
- Analytical purity: 50%
- Stability under test conditions: the test substance was subjected to a compositional analysis at the end of the study, which confirmed the stability of glutaraldehyde throughout the experimental period.

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: from Microbiological Associates (Walkersville, MD)
- Age at study initiation: at test starting the animals were 55 days old
- Weight at study initiation: on date of receipt, the mice were 45 days old and weighed between 15 and 25 g
- Housing: two per cage, separated by test group and sex, in stainless steel, wire-mesh cages
- Diet (e.g. ad libitum): powdered NIH-07 feed (Batch #35-553, 4-30-79, Zeigler Brothers, Inc. , Gardners, PA), ad libitum
- Water (e.g. ad libitum): Tap water, ad libitum
- Acclimation period: ca. 3 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 - 27
- Humidity (%): 42 - 62
- Air changes (per hr): 16 (inhalation chamber)
- Photoperiod (hrs dark / hrs light): 12 hrs/ 12 hrs

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Remarks on MMAD:

MMAD / GSD: Not considered

Details on inhalation exposure:

VAPOR GENERATION:
- Glutaraldehyde vapor was generated by means of vapor generators developed by the Special Instrumentation Division of Union Carbide Corporation.
- Air was drawn through a dehumidifier and was then heated and conducted into a rotating evaporator tube into which the liquid solution to be vaporized was metered; the hot air evaporated the sample and the vapor further was diluted at the chamber air intake.

EXPOSURE REGIMENT:
- 6 hours of exposure per day for 5 consecutive days
- Resting period of 2 days
- 6 hours of exposure per day for 4 consecutive days

MONITORING OF TEMPERATURE AND HUMIDITY IN THE CHAMBER:
The temperature and humidity within the inhalation chamber were monitored at least 4 times during each 6-hour exposure period.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Approximatively once an hour, air samples from the inhalation chamber were taken and were subjected to concentration analysis by means of a Perkin Elmer 3920B dual column gas chromatograph.

Duration of treatment / exposure:

9 days

Frequency of treatment:

- Total exposure number: 9
- Each exposure: 6 hours

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0.2 ppm (nominal)

Remarks:

0.00083 mg/l (analytical conc.)

Doses / concentrations 2

Dose / conc.:

0.63 ppm (nominal)

Remarks:

0.0026 mg/l (analytical conc.)

Doses / concentrations 3

Dose / conc.:

2.1 ppm (nominal)

Remarks:

0.0087 mg/l (analytical conc.)

No. of animals per sex per dose:

Ten animals per sex were assigned to each of the three test groups and the control group.

Control animals:

yes, sham-exposed

Examinations

Observations and examinations performed and frequency:

MORTALITY AND CLINICAL SYMPTOMS:
All animals were observed prior to, during, and following exposure for any abnormalities in appearance, respiration, or general behavior.
BODY WEIGHT:
All animals vere weighed prior to the first exposure. The values obtained were used as the pre-exposure reference weights and were subtracted from each subsequent weight to determine the change in body weight. The animals were also weighed an the morning preceding the
second, fifth, sixth, and seventh exposures, and prior to sacrifice.

FOOD CONSUMPTION:
Food consumption was determined weekly for each cage of rats starting five days prior to the initiation of exposure. The amount of feed
consumed was divided by the number of rats per cage.

Water consumption.
Not considered.

OPHTHALMOSCOPIC EXAMINATION:
The ophthalmologic examination was performed using a light and magnifying lens to observe the anterior chamber of the eye.The corneas of all animals were examined prior to exposure, upon death, or at sacrifice.

HAEMATOLOGY AND CLINICAL CHEMISTRY:
Not considered.

URINALYSIS:
Not considered.

NEUROBEHAVIOURAL EXAMINATION:
The animals were subjected to a functional observational battery (modified Irwin Screen Test). The modified Irwin Screen Test was conducted on 5 rats/sex of the 2.09 ppm group (tested prior and after the first, second, fifth and sixth exposure, and prior sacrifice) and on 5 rats/sex of the 0.63 ppm group (tested prior sacrifice). The animals of the 0.20 ppm and the control groups were not screened.
Following parameters were considered: corneal response, pupil response, tail pinch, toe pinch, righting reflex, locomotor activity, impaired gait, respiration, tremors, convulsions, salivation, piloerection, diarrhea, tail elevation, lacrimation, stereotypy.

Sacrifice and pathology:

Animals that died or had to be sacrificed in extremis because of bad state of health during the experiment were subjected to necropsy; the survivors were sacrificed at the end of the experiment.

ORGAN WEIGHT:
Organ weighing (absolute and relative) of liver, lungs, kidneys and testes (males) was done;

GROSS PATHOLOGY AND HISTOPATHOLOGY:
Gross pathological examination was done, and tissues were collected from animals showing abnormalities and were stored for possible future histologic evaluation.

Statistics:

The statistical assessment of the findings was based on Bartlett´s test for homogeneity of variance, on the analysis of variance and on Duncan´s multiple range test. Depending on the results of these tests, Student´s test, the Cochran t-test and Fisher´s exact test were considered

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

The rats of both sexes treated with 2.1 and 0.63 ppm displayed a series of symptoms including lacrimation, nasal discharge, salivation, mouth breathing and labored respiration. These symptoms were more prominant in the 2.1 ppm group and became more severe towards the end of the experimental period. Intermittent and slight nasal discharge, lacrimation and salivation also were noticed in the 0.20 ppm group.

Mortality:

mortality observed, treatment-related

Description (incidence):

Nine of ten males and seven of ten females of the 2.1 ppm group and one male of the 0.63 ppm group died predominantly during the second half of the experimental period.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Both males and females of the 2.1 ppm group showed statistically significant reductions in body weight change when compared to controls (7 to 8% body weight loss after the first exposure; 38% loss for the only surviving male and 34% loss for the surviving females at the end of the experiment). A statistically significant reduction in body weight gain also was reported for the 0.63 and 0.20 ppm males and for the 0.63 ppm females.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption for males and females of the 2.1 and the 0.63 ppm groups was significantly reduced compared to control (respectively 5% of control values after 4 exposures for the 2.09 ppm group, and 26% of control values after 9 exposures for the 0.63 ppm group). In the 0.20 ppm group, reduction in food consumption only was reported for the males.

Ophthalmological findings:

effects observed, treatment-related

Description (incidence and severity):

Dullness of the cornea was seen in 5/9 males and 2/7 females of the 2.1 ppm group that died during the experimental period. The only male survivor of the 2.1 ppm group exhibited keratitis.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Because of the reduced number of male survivors in the 2.1 ppm group, organ weight was not considered. For the males of the 0.63 ppm group, following findings were reported: Significant decrease in absolute liver weight (49%), absolute lung weight (15%), absolute kidney weight (22%) and absolute testes weight (17%); significant decrease in relative liver weight (20%) and significant increase in relative lung weight (37%), relative kidney weight (25%) and relative testes weight (30%). For the 0.63 ppm females, a significant decrease in relative liver weight (16%) and increase in relative lung weight (27%) were reported.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

The main pathological findings reported for the animals of the 2.1 ppm group were findings that are commonly seen in case of autolysis (9/10 males and 7/10 females died during the experiment). Females of the 2.1 and the 0.63 ppm groups displayed gas in their stomach and intestines; this finding was seen as a consequence of mouth breathing and gasping. In males of the 2.1 ppm group, necropsy revealed a significantly increased incidence of corneal dullness, nasal discharge and congestion of the nasal cavity.

Description (incidence and severity):

Because of autolysis or congestion, no histopathological assessment of the findings in the nasal cavity was possible.

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Modified Irwin Screen Test:
The males and females of the 2.09 ppm group showed hypoactivity, abnormal righting reflex, impaired gait, slow corneal response, small pupils and slow locomotor activity. In the 0.63 ppm group, two males and three females suffered from abnormal breathing (abdominal and mouth); one female further showed lacrimation, small pupils, showed corneal response and decreased locomotor activity.

Effect levels

Dose descriptor:

LOAEC

Effect level:

0.2 ppm

Sex:

male/female

Basis for effect level:

other: clinical symptoms (lacrimation, nasal discharge, salivation) reduction in food consumption and body weight gain (males) sensory irritation

Remarks on result:

other: 8.4E-3 mg/L air (analytical)

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Repeated exposure of rats to glutaraldehyde vapor for nine days at 2.09, 0.63 and 0.20 ppm resulted in mortalities at the highest tested concentration, whereas at the two lower concentrations, sensory irritation, reduction in feed consumption and in body weight gain and clinical symptoms including nasal discharge, lacrimation and salivation, were observed. Thus the LOAEC was 0.2 ppm, corresponding to 0.00083 mg/l air.