(Z)-1,3-dichloropropene

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

repeated dose toxicity: inhalation, other

Remarks:

other: 9 exposures of 6 hours each

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

10 July 1989 to 27 September 1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP-compliant but non-guideline study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of the study was to determine the potential inhalation toxicity of cis-DCP in rats exposed for 6 hours/day,5 days/week for 9 exposures in order to supplement existing data to provide additional information for safe handling of the chemical.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

cis-1,3-dichloropropene

IUPAC Name:

cis-1,3-dichloropropene

Details on test material:

Source: Shell International, Netherlands
Lot No. 2047
Purity (by Shell): 94.3% cis siomer, 1.5% trans isomer, 0.2% 1,2-dichloropropene
Purity (by Hardas 1989) 95.6% cis isomer identified by infrared spectroscopy (Putzig 1989)
Molecular formula: C3H4Cl2
Molecular weight 111 g/mol
Vapor pressure: 34.3 mm Hg at 25 deg C and 760 Torr
Boiling point: 104 deg C
Physical state: liquid
Maximum vapor concentration: 45131 ppm at 25 dec C

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

Source: Charles River Breeding Laboratory, Kingston NY
Age: 6 weeks old at purchase
Acclimatisation period: 13 days, weighed randomly assigned exposure groups
Environment: maintained at 21 deg C, 50% relative humidity, 12 hour light/dark cycle
Diet: water and food (Ralston Purina Co.) provided ad libitum

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

Chambers: 1000 L stainless steel and glass Rochester type with 90 cm cube with pyrmaid top and bottom
Generating stystem: test material metered into glass J-tube concurrently with heated (100 deg C) compressed air to vaporize material
Chamber monitoring: Flow calibrated prior to start of study, airflow maintained at 225L/min, 22 deg C, 50% rel. humidity (recorded hourly)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Determined 10-11 times/ exposure period with infrared spectrophotometer at 12.8 umand signal was interpolated with the response generated from vapor standards of known concentrations. Standards prepared by injecting measured volumes of liquid test material in to bags with measured volumes of compressed air. Distribution of test material was determined from at least 5 sample points in the breathing zone and reference point in the chamber. All values were within 10% of the mean reference point value.

Duration of treatment / exposure:

6 h/d

Frequency of treatment:

5 d/wk
9 exposures

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 10, 60, or 150 ppm
Basis:
nominal conc.

No. of animals per sex per dose:

15/sex
5/sex/dose subjected to gross and histopatholgical necropsy

Control animals:

yes

Details on study design:

Groups of 15 male and 15 female rats were exposed to 0, 10, 60 or 150 ppm (0.0, 0.05, 0.27 or 0.68 mg/liter) vapors of the test material for 6
hours/ day,5 days/week for 9 exposures. Whole-body exposures occurred under dynamic airflow conditions. Animals were observed daily and body
weights were recorded on test days 1,3,5,8 and 11. On the day after the last exposure, 5 male and 5 female rats/ exposure level were necropsied. Major organs were weighed and selected tissues were evaluated histopathologically. Groups of five animals/sex/exposure level were used to determine
nonprotein sulfhydryl content in the liver, kidney and lung at 1 and at 18 hours, respectively, following the last exposure.

Examinations

Observations and examinations performed and frequency:

Rats observed daily for overt signs of toxicity. Clinical examination per rat on day 5 (skin, fury, eyes, mucous membranes, respiration, nervous system and behaviour pattern with particular attention to lethargy, tremors, convulsions, salivation, lacrimation and diarrhea and other CNS dysfunction. Additional daily observation and routine monitoring on weekends was limited to removal of dead animals and feed/water. Animals weighed on days 1, 3, 5, 8, and 11.

Sacrifice and pathology:

Rats (5/sex/dose) were fasted overnight and necropsied the day following last exposure. Animals were weighed, anaesthetized with methoxyflurane and humanely euthanized. Weights of the following organs were recorded: brain, lung, heart, liver, kidneys, adrenals and testes. Each animal was examined for gross alterations.
Ophthalmological examinations conducted prior to start of study with pen-light illumination technique and at scheduled necropsy using moistened slide/fluorescent light technique
The following tissues were collected from animals and preserved in neutral phosphate buffered formalin: adrenals, aorta, auditory sebaceous glands, bone, bone marrow, brain, cecum, cervix, coagulating glands, colon, duodenum, epididymides, esophagus, eyes, gross lesions, heart, ileum, jejunum, kidneys, lacrimal/harderian glands, larynx, liver, lung (perfused), mammary gland, mediastinal lymph node, mediastinal tissues, mesenteric lymph node, mesenteric tissues, oral tissues, ovaries, oviducts, pancreas, parathyroid glands, peripheral nerve, pituitary, prostate, rectum, salivary glands, seminal vesicles, skeletal muscle, skin, spinal cord, spleen, stomach, testes, thymus, thyroid gland, tongue, trachea, urinary bladder, uterus, and vagina.
Histopathological examination in control and high concentration group was limited to nasal cavity, larynx, lungs, liver, and urinary bladder. Nasal tissues (4 sections) were examined from all rats exposed to 10 or 60 ppm.

Other examinations:

Rats (5/sex/dose) - nonprotein sulfhydryl determination was performed 1 or 18 h after the last exposure to determine recovery to the next exposure period. Liver, lung, and kidney were excised and weighed, non protein sulfhydryl content of tissues was determined (method of Sedlak and Linsay 1969)

Statistics:

Chamber concentration, temperature, relative humidity and airflow are reported with descriptive statistics.
All remaining parameters examined statitically were first tested for equality of variance using Bartlett's test. If results were rejected the parameter was flagged for further examination. Otherwise all parameters subjected to appropriate parametric analysis by ANOVA.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

All animals survived, rats exposed to 150 ppm appeared lethargic during first exposure but not subsequent expsoures; other clincial data showed no eeffect

Mortality:

no mortality observed

Description (incidence):

All animals survived, rats exposed to 150 ppm appeared lethargic during first exposure but not subsequent expsoures; other clincial data showed no eeffect

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Dose dependent decreased of male and female mean body weigths at 60 or 150 ppm.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Several absolute and relative organ weights of amle and female rats expsoed to 150 ppm and lkesser extent 60 ppm were statistically different from controls (due to decreases in terminal body weights). At 150 ppm, increases in absolute and relative adrenal

Gross pathological findings:

no effects observed

Description (incidence and severity):

observations considered to be incidental and typical of rat strain

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Nasal cavity: male and female rats exposed to 50 ppm had moderate bilateral hyperplasia of the respiratory epithelium, moderate bilaterl dgeneration of the olfactory epithelium and exudate in nasa passages.

Details on results:

Observations:
All animals survived the nine exposures to 10, 60 or 150 ppm cis-DCP. Rats exposed to 150 ppm appeared to be lethargic during the first
exposure but this was not observed in subsequent exposures. There were no other clinical observations related to exposure to the test material

Body Weights:
Mean body weight values for male and female rats exposed to 60 or 150 ppm cis-DCP were statistically decreased from control values. Animals exposed to 60 or 150 ppm lost weight following the initial exposures; rats exposed to 150 ppm gained very little weight during the remainder of the study whereas animals exposed to 60 ppm subsequently achieved near normal weight gains. By the end of the second week the average body weight of animals exposed to 60 ppm was only depressed 3% from control values. Body weights of male and female rats
exposed to 10 ppm were comparable to control values.

NPSH Determinations:
Statistical decreases were noted in the liver NPSH levels of male rats exposed to 60 and 150 ppm at 1 hour after the last exposure to cis-DCP; however, statistical increases were noted in the liver NPSH levels of both male and female rats at 18 hours after exposure to 60 or 150 ppm. In the
kidney, statistically significant decreases were noted in male rats exposed to 150 ppm at one hour. Statistically significant increases were noted in the kidney NPSH levels of female rats sacrificed 1 and 18 hours after exposure to 60 ppm and in male and female rats sacrificed 18 hours after exposure to 150 ppm. Lung NPSH levels for male and female rats exposed to 150 ppm were slightly but statistically significantly decreased one hour after exposure and statistically significantly increased 18 hours after exposure.

Organ Weights:
Terminal body weights of male and female rats exposed to 150 ppm cis-DCP were statistically decreased from control values. Terminal body weights of rats exposed to 60 ppm, most notably male rats, were also decreased from control values. Due to these decreases in body weight, several absolute and relative organ weights of male and female rats exposed to 150 ppm, and to a lesser extent 60 ppm, were statistically different
from control values. At 150 ppm, these included increases in absolute and relative adrenal weight and relative brain, heart, kidney, lung and testes
weights. The absolute heart and liver weights were also decreased. Male and female rats exposed to 60 ppm also had statistically decreased relative brain and kidney weights. Similar changes in absolute and relative organ weight changes have been noted in animals on a feed-restricted diet (Oishi et al., 1979). Hence, the observed differences in organ weights were probably secondary to differences in body weights, which was probably the result of decreased feed consumption due to stress or olfactory mucosal lesions in the nose, and were not considered to be reflective of direct effects of the test material on a particular organ.

Pathology:
At necropsy, all of the gross observations were considered to be spontaneous, incidental and typical of this rat strain.
Histopathologic effects related to exposure were confined to the nasal cavity of male and female rats exposed to 150 ppm cis-DCP. These included moderate bilateral hyperplasia of the respiratory epithelium, moderate bilateral degeneration of the olfactory epithelium and exudate in the nasal
passages. The respiratory mucosa of the nasal cavity, which normally consists of 1 to 2 cell layers of cuboidal cells, was thickened to as many as 4 cell layers thick (graded as moderate). Degeneration of the olfactory mucosa was characterized by desquamation of necrotic epithelial cells and an overall decreased thickness of the epithelium. The epithelial lining is 6-7 cell layers thick in control animals but occasionally was only 1-2 cell layers thick (graded as moderate) in animals exposed to 150 ppm. The nasal exudate was composed of serous fluid mixed with leukocytes and was located in the dorsal meati. The exudate was also often closely applied to remaining olfactory epithelium in these regions. Male and female rats exposed to 10 or 60 ppm cis-DCP did not have microscopic changes in nasal tissues. All remaining histopathologic observations noted were considered to be spontaneous, incidental and typical for this strain of rats.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

60 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Changes in body weight; non protein sulfhydryl levels at 1 h in liver, kideny and lung; and histopathological changes of moderate severity in the respiratory and olfactory mucusoa in the nasal cavity in male and female rats exposed ot 150 ppm.

2

Dose descriptor:

LOAEL

Effect level:

150 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Changes in body weight; non protein sulfhydryl levels at 1 h in liver, kideny and lung; and histopathological changes of moderate severity in the respiratory and olfactory mucusoa in the nasal cavity in male and female rats exposed at 150 ppm.

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The no-adverse-effect-effect level (NOAEL) was 60 ppm based on decreased body weight, changes in non protein sulfydryl levels in liver, kidney and lung after 1 h exposures, and histopatholigcal changes in nasal cavity of male and female rats exposed to 150 ppm (LOAEL).

Executive summary:

A GLP-compliant study was conducted to a non-guideline method in order to supplement existing data on the inhalation toxicity of the substance.

 

Male and female rats exposed to 150 ppm cis-DCP lost weight during the course of the two-week study. Body weights of male and female rats exposed to 60 ppm were slightly decreased (3%) from control values at the end of the study. There were apparent exposure concentration-related decreases in liver, kidney and lung NPSH levels for male rats exposed to 150 ppm cis-PCP, as well as a decrease in liver NPSH for males in the 60 ppm exposure group when measured one hour after exposure. However, the NPSH values in all of these tissues were higher than control values by 18 hours post-exposure, and there were no associated gross or histopathologic changes in liver, kidneys or lungs. The NPSH measurements for females were unremarkable. Histopathologic examination revealed changes of moderate severity in the respiratory and olfactory mucosa in the nasal cavity of males and female rats exposed to 150 ppm cis-DCP; there were no exposure-related histopathologic changes in animals in the two lower exposure groups. Thus the no-adverse-effect-level (NOAEL) was 60 ppm.