Tetrachlorophthalic anhydride

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

No functional observations and ophthalmological examinations; fluctuations in chamber concentrations

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tetrachlorophthalic anhydride

EC Number:

204-171-4

EC Name:

Tetrachlorophthalic anhydride

Cas Number:

117-08-8

Molecular formula:

C8Cl4O3

IUPAC Name:

tetrachloro-1,3-dihydro-2-benzofuran-1,3-dione

Details on test material:

- Name of test material (as cited in study report): Tetrathal
- Supplier: Monsanto Chemical Company
- Physical state: fines-dust form

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 Breeding Laboratories
- Age at study initiation: 53 days
- Weight at study initiation: males 271 g (244-295), females 170 g (138-194)
- Diet (e.g. ad libitum): Purina Laboratory Rodent Chow 5001
- Water (e.g. ad libitum): tap water
- Acclimation period: 2 weeks

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Remarks on MMAD:

MMAD / GSD: 0.5 mg/m3 dose group: 2.69 µm/1.90-11.58 (The range of geometric standard deviation for 11 of the 13 samlples was 1.90 to 4.99, the other two value of 10.69 and 11.58 may have resulted from a sampling error);
5.0 mg/m3 dose group: 3.34 µm/2.07-4.53
50 mg/m3 dose group: 3.45 µm/1.80-4.25

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel and glass chambers in which the animals were exposed had a total volume of one cubic meter with an effective exposure volume of 760 liters.
- Source and rate of air: operated dynamically at an air flow rate of approximately 288 liters per minute. This flow rate provided one complete air change every 3.6 minutes and a 99% equilibrium time (T99) of 16.1 minutes.
- System of generating particulates/aerosols: The test material Fines Dust Form, was sieved through a 60-mesh sieve and hand packed into a cylinder of a Wright dust-feed mechanism. Appropriate exposure concentrations were achieved by adjusting the gear ratios of the dust-feed mechanism and by varying the air flow through the dust-feed mechanism.
- Method of particle size determination: Particle size distribution assessment was made once a week using a Batelle cascade impactor.


TEST ATMOSPHERE
- Brief description of analytical method used: The initial method selected to analyze chamber concentrations was to utilize the GCA Respirable Dust Monitor (Model 201). A different method was initiated on Week 6. The test material was collected on a glass fiber filter, extracted with hot water, an alliquot was taken and the absorbance measured at 213 nm on the Hitachi Model 110-40 uV/Vis spectrophotometer. A calibration curve, comparing known concentrations of the test material in water versus absorbance, was prepared. Chamber concentrations beginning with Week 6 were calculated by comparing the total amount of material collected to the total volume of air sampled. Exposure levels for the first five weeks of the study have been extlapolated based on a regression analysis comparing daily nominal concentration and daily average concentrations from Weeks 6 through 13.
- Samples taken from breathing zone: yes

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Chamber concentrations were analyzed using a GCA Respirable dust monitor for the first 5 weeks and then spectrophotometrically during the remainder of the study. Analytical exposure levels for the first 5 weeks were calculated by extrapolation based on regression analysis of daily nominal concentrations. Daily analytical concentrations were used for the last 8 weeks of the study. Correlation coefficients for regression analysis of analytical and nominal concentrations was 0.97 for the low, mid and high doses combined, and was 0.90 for the high and mid dose, but only 0.50 for the low dose; hence the low dose level may not be accurately described.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

6 hours/day, 5 days/week

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0, 0.5, 5 and 50 mg/m3
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
0, 0.73, 4.15 and 36.3 mg/m3
Basis:
analytical conc.

No. of animals per sex per dose:

15

Control animals:

yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily


BODY WEIGHT: Yes
- Time schedule for examinations: weekly from 12 days prior to exposure through termination


HAEMATOLOGY: Yes
- Time schedule for collection of blood: week 7 and 13
- Anaesthetic used for blood collection: No, collected by venipuncture of the orbital sinus
- Animals fasted: Yes
- How many animals: 15/sex
- Parameters checked: hemoglobin, hematocrit, erythrocyte count, clotting time, total and differential leukocytes


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: week 7 and 13
- How many animals: 15/sex for the control and high dose group
- Parameters checked: alkaline phosphatase, blood urea nitrogen, serum glutamic pyruvic transminase and blood glucose


URINALYSIS: Yes
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data
- Parameters checked: appearance, bilirubin, ketones, glucose, occult blood, pH, protein, specific gravity, microscopic examination

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
15 animals/sex/group were sacrificed by exsanguination under ether anesthesia. The organ weight of liver, lungs, pituitary and spleen were measured. Tissues fixed and histopathologically examined were: adrenals (2), bone marrow (sternal), brain (3 sections including frontal cortex and basal ganglia, parietal cortex and thalamus; cerebellum and pons), eyes (2), gonads (ovaries, testes and epididymides), mammary gland (right inguinal), pancreas, pituitary, salivary gland (right submaxillary), skeletal muscle (right biceps femoris), skin (right inguinal), spinal cord, spleen, stomach, heart (with coronary vessels), intestine (colon, duodenum, ileum), kidneys (2), liver (2 sections), lung and mainstem bronchi, lymph node (mesenteric), thyroid/parathyroid, urinary bladder, uterus/prostrate, gross lesions, tissue masses.

Statistics:

Mean group values for body weights, organ weights and weight ratios were evaluated statistically using Dunnett's test. The F-test and Student’s t-test were used to compare group means for hematology and clinical chemistry parameters. When variances were observed in the F-test, a Student’s t-test, as modified using Cochran's approximation test was employed. All comparisons were made at both the 5% and 10% level of significance.

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY: All animals survived the study duration. Physical observations were limited to the high dose group, and consisted of increased nasal discharge, ano-genital staining and excessive lacrimation.


BODY WEIGHT AND WEIGHT GAIN: Body weight gains for all levels for both sexes were considered comparable to controls.


HAEMATOLOGY: no treatment related effects were observed.


CLINICAL CHEMISTRY: no treatment related effects were observed.


URINALYSIS: High dose males exhibited slight proteinuria at 7 weeks and 13 weeks. Microscopic examination of the urine revealed a slight increase in the amount of amorphous matter in the urine after 13 weeks.


ORGAN WEIGHTS: An significant increase in absolute and relative lung weights (p ≤ 0.01) in the mid-dose & high-dose males, and high-dose females were considered treatment-related. The percentage increase in the relative lung weight in the mid and high dose males were 24 and 62, respectively. Similarly, the percentage increase in the relative lung weight in the mid and high dose females were 7 and 25, respectively. The several other small changes in organ weights or ratios were considered unrelated to treatment since there was no dose-response evident.


GROSS PATHOLOGY: The only gross pathological observation attributable to treatment was the appearance of petechial hemorrhages in the lungs of several treated rats.


HISTOPATHOLOGY: NON-NEOPLASTIC: Histopathological changes in the lungs were also noted in all doses groups. Irregular thickening of the alveolar septa, noted in all dose groups. Irregular thickening of the alveolar septa, scattered pigmented macrophages and multinucleate giant cells, multifocal accumulation of alveolar macrophages and multifocal alveolar hemorrhages were noted. High dose animals also exhibited mild centrilobular hepatocellular hypertrophy.

Effect levels

1

Dose descriptor:

NOAEC

Effect level:

0.73 mg/m³ air (analytical)

Sex:

male/female

2

Dose descriptor:

LOAEC

Effect level:

4.15 mg/m³ air (analytical)

Sex:

male/female

Basis for effect level:

other: lung weight and histological changes

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Cumulative mean analytical concentrations were 0.73, 4.15, and 36.3 mg/m3 respectively based on spectrophotometric analysis of chamber samples. Although the mean analytical chamber concentrations for the low and mid level appear close to target levels, extreme variations in chamber concentrations were observed from day to day and also during any given day. At the high dose level, similar daily excursions occurred. In general, during weeks 2 through 5, animals appeared to have been exposed to concentrations well below the target levels.