Reaction mass of m-terphenyl and o-terphenyl

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted from November 28, 1983 through December 14, 1983

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study, GLP-compliant, available as unpublished report, no restrictions, adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Terphenyl

EC Number:

247-477-3

EC Name:

Terphenyl

Cas Number:

26140-60-3

Molecular formula:

C18H14

IUPAC Name:

terphenyl

Test material form:

solid

Details on test material:

- Name of test material: Mixture of toluol soluble terphenyls and quarterphenyls
- Substance type: a mixture of terphenyls and quaterphenyls
- Physical state: An amber solid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl: CD®(SD)BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratory (Portage, Michigan)
- Age at study initiation: approximately 5 weeks
- Weight at study initiation: males weighing 160 to 186 grams and females 135 to 158 grams
- Housing: individually housed in suspended stainless stell wire mesh cages
- Diet (e.g. ad libitum): ad libitum; Purina Laboratory Certified Rodent Chow ®(5002), except during the exposure period
- Water (e.g. ad libitum): ad libitum; tap water (St. Louis City, MAO), except during the exposure period
- Acclimation period: eight days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 68-760F
- Humidity (%): 35-60% relative humidity
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark cycle

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The exposure atmosphere was generated by using a Laskin-type nebulizer utilizing double spray jets.
- Exposure chamber volume: The exposure chamber was a 0.3 m³ Rochester-type stainless steel chamber, with a pyramidal top and bottom and a glass window in the door
- Source and rate of air: Airflow through the chamber ranged from 20.0 to 22.9 liters/minute.
- Method of conditioning air: Test material (heated and melted) was placed in a 3-neck flask and a Laskin nebulizer was positioned in the liquid of the flask. Exposures were conducted under two sets of conditions: (a) test material heated and exposure chamber at ambient temperature and (b) both test material and exposure chamber heated. Control (room air) exposures were conducted at ambient and elevated chamber temperatures. A three-foot piece of heat tape was wrapped around the flask and connected to a 12UV variable autotransformer to heat the test material. The chamber atmosphere was heated by the use of two six-foot heat tapes attached to the outer chamber sides and controlled by a 120V variable autotransformer.
- Temperature, humidity, pressure in air chamber: The chamber atmosphere mean temperatures ranged from 23.3-24.7°c (ambient) and 38.0-39.0°c (heated). The relative humidity of the chamber atmospheres ranged from 35-47%. Oxygen levels were measured using a Teledyne oxygen analyzer and were maintained at 20% or greater for all exposures.

TEST ATMOSPHERE
- Brief description of analytical method used: The analytical concentration of test material in iso-octane was determined by gas chromatography. The nominal concentration was calculated once for each exposure by determining the total amount of test material delivered by the nebulizer into the chamber and dividing this amount by the total air volume passing through the chamber during the exposure period. Particle-size analysis was performed using an Andersen cascade impactor (Andersen Samplers Inc., Atlanta, GA).
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (Table 2)
- Particle size distribution: The percentage of particles less than 10 microns in the chamber ranged between 99.0 and 99.1.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMAD for the exposures was between 2.27 and 2.38 microns, with the geometric standard deviation between 1.83 and 1.90.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Impinger samples were collected during this LC50 study by the Inhalation Toxicology Group. Samples were analyzed by gas chromatography with a flame ionization detector based on measurement of all the components.

Duration of exposure:

4 h

Concentrations:

3.6, 3.7, 3.8 mg/L

No. of animals per sex per dose:

6 animals per sex per dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: All animals were examined following exposure and gross signs of toxicity were recorded. During the 14-day post-exposure period, the animals were examined twice daily (morning and afternoon) and gross signs of toxicity were recorded except on weekends when only mortality checks were done. Body weights and toxicity observations were also obtained on post-exposure Days 2, 7, and 14.
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 3.8 mg/L air

Exp. duration:

4 h

Mortality:

No deaths occurred (See Table 1).

Clinical signs:

other: During exposure observations in the 3.8 mg/L, 3.7 mg/L and heated control groups salivation and red material were found around eyes (in 3.7 mg/L group only). Discharge from nose was observed in the 3.6 mg/L group. Immediate post-exposure observations incl

Body weight:

All groups gained body weight throughout the post-exposure period.

Gross pathology:

There were no gross pathology abnormalities observed in any of the animals during necropsy examinations.

Any other information on results incl. tables

Three groups of six male and six female rats per group were exposed once to atmospheres of aerosolized test item. Two additional exposures (controls) were performed using house-conditioned air only. All chamber atmospheres were heated during exposure except for one control exposure and one test item exposure. No deaths occurred. The mean exposure levels ranged from 3.6 mg/L to 3.8 mg/L. Therefore, the LC50 is assumed to be greater than 3.8 mg of the test item per liter of air. The nominal/analytical concentration ratios indicate some preferential impaction of the test material on the animals, cages, and chamber walls (Table 1). Particle-size analyses, including mass median aerodynamic diameter (MMAD), geometric standard deviation, and percent of particles less than 10 microns, are given for each test exposure level in Table 2. The percentage of particles, in the chamber, less than 10 microns ranged between 99.0 and 99.1. The MMAD for the exposures was between 2.27 and 2.38 microns, with the geometric standard deviation between 1.83 and 1.90.

During exposure observations in the 3.8 mg/L, 3.7 mg/L and heated control groups were salivation and red material around eyes (in 3.7 mg/L group only). Discharge from nose was observed in the 3.6 mg/L group.

Immediate post-exposure observations included red encrustation about eyes and nose, laboured breathing, salivation, wet fur on-the ventral side (due to salivation), and fur coated with test material (Table 3). Salivation, wet fur on the ventral side (due to salivation), and red encrustation about the nose were also noted on the heated chamber control animals. Post-exposure Day 2 signs of toxicity included red encrustation about eyes and nose and fur coated with test material (Table 4). On post-exposure Days 7 and 14, these observations were no longer evident. No observations were seen in the control groups during post-exposure Days 2, 7, and 14.

All groups gained body weight throughout the post-exposure period (Table 5). There were no gross pathology abnormalities observed in any of the animals during necropsy examinations.

In conclusion, toluol soluble terphenyl and quarterphenyls at mean exposure concentrations of 3.6 to 3.8 mg/L in air caused some very short-term irritation to the respiratory tract and sensory organs. In the absence of any deaths, the LC50 is assumed to be greater than 3.8 mg/L.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 for Mixture of toluol soluble terphenyls and quarterphenyls was determined to be above the maximum attainable concentration of 3.8 mg/L air (males/females)

Executive summary:

Three groups of 6 male and 6 female Sprague-Dawley rats per group were each exposed once for 4 hours to atmospheres of aerosolized a Mixture of toluol soluble terphenyls and quarterphenyls. Mean exposure concentrations ranged from 3.6, 3.7 and 3.8 mg of the test item (vapour/aerosol) per liter of air. 3.8 mg/L was the higher attainable mean concentration. The chamber atmospheres were operated at elevated ambient temperatures. Three single-concentratinos exposures (two concentrations with heated chamber air and test material and one with ambient chamber air and heated test material) and two control exposures (ambient house-conditioned or heated chamber air) were performed. Exposure was followed by a 14 -day observation period and subsequent necropsy. No death occurred at the higher attainable level or lower levels. During the exposure observations included salivation, red material around eyes, and discharge from nose. Immediately after exposure, notable observations included red encrustation around the nose and eyes, laboured breathing, salivation, wet fur on the ventral side (due to salivation), and fur coated with test material. Post-exposure observations included red encrustation around eyes and nose and fur coated with test material. By post-exposure Day 7, all animals appeared in good health. All animal groups gained weight throughout the 14 -day post-exposure period. Terminal necropsy findings indicated that there were no gross abnormalities in any of the test animals. Based on the test results, the test item at mean exposure concentrations of 3 .6 to 3.8 mg/L in air caused some short term irritation to the respiratory tract and sensory organs. The LC50 for the test item is assumed to be greater than 3.8 mg/L, which was the maximum attainable concentration.