1,2,3,4-tetrahydroisoquinoline

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF AG experimental toxicology and ecology

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,2,3,4-tetrahydroisoquinoline

EC Number:

202-050-0

EC Name:

1,2,3,4-tetrahydroisoquinoline

Cas Number:

91-21-4

Molecular formula:

C9H11N

IUPAC Name:

1,2,3,4-tetrahydroisoquinoline

Details on test material:

- Name of the test substance used in the study report: 1,2,3,4-Tetrahydroisoquinoline
- Purity: 93.2 area-% (analytical report 08L00186)
- Physical state / appearance: liquid / yellowish, clear
- Storage conditions: room temperature
- Test substance number: 05/0797-2
- Batch number: 0640710217
- Date of production: Feb 2006
- Homogeneity: homogeneous
- Stability: The stability under storage conditions over the study period was guaranteed by the sponsor

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd Laboratory Animal Services, Wölferstrasse 4, CH-4414 Füllinsdorf, Switzerland
- Reasons for selection of the test species: Rats were selected since this rodent species is recommended in the respective test guidelines. Wistar rats were selected since there is extensive experience available in the laboratory with this strain of rats. The Wistar strain is selected because a huge amount of historical control data are available for this strain.
- Age at study initiation: male 8-10 weeks, female 10-12 weeks
- Weight at study initiation: male 250-288 g, female 196-206 g (group mean weight ranges)
- Housing: single housing in H-Temp (PSU) cages, floor area about 800 cm2 (425x266x185 mm); TECNIPLAST, Germany; bedding: Type Lignocel FS14 fibres, dustfree bedding supplied by SSNIFF, Soest, Germany; enrichment: Wooden gnawing blocks (Typ NGM E-022); Abedd ® Lab. and Vet. Service GmbH Vienna, Austria
- Diet: Kliba-Labordiät (Maus / Ratte Haltung “GLP”), Provimi Kliba SA, Kaiseraugst, Basel, Switzerland, ad libitum
- Water: tap water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24;
- Humidity (%): 30-70;
- Air changes (per hr): fully air-conditioned;
- Photoperiod (hrs dark / hrs light): 12/12 (6.00 am - 6.00 pm/6.00 pm - 6.00 am);

Administration / exposure

Route of administration:

other: inhalation: vapour and liquid aerosol

Type of inhalation exposure:

other: whole body and head/nose

Vehicle:

air

Details on inhalation exposure:

GENERATION OF THE INHALATION ATMOSPHERE
Test substance preparation: The test substance was dosed unchanged.

- Test group 1:
Equipment: Vaporizers (glasses with thermostat), Thermostats (Lauda), Continuous infusion pump Perfusor (B. Braun).
Generation technique: Vapor atmosphere was generated, contained liquid aerosols fraction. For the test group the test atmosphere was generated by supplying amounts of the test substance to a heated vaporizer by means of the pump. The mixtures that developed were taken up by the supply air and passed into the exposure system.
Generator temperature: 90°C
- Test group 2 - 4:
Equipment: Two-component atomizer Mod. 970 (stainless steel, Schlick); Continuous infusion pump Perfusor (B. Braun).
Generation technique: Liquid aerosols were generated contained vapor fraction. For each test group the aerosols were produced by continuously pumping amounts of the test substance to a two-component atomizer. Using compressed air, the aerosol was produced with the atomizer inside the exposure system.

EXPOSURE
- Test group 1:
Whole-body inhalation system: IKA 02 (glass-steel construction), BASF SE, volume V ≈ 200 L: the animals were kept singly in compartmentalized wire cages, and were exposed inside the chamber.
- Test group 2 – 4:
Head-nose inhalation system INA 20 (glass-steel construction, BASF SE, volume V ≈ 55 L): the animals were restrained in glass tubes and their snouts projected into the inhalation system.
The homogenous distribution of test substance atmospheres in these inhalation systems has been verified with model aerosols / vapors.
The exposure system was located inside an exhaust cabin in an air-conditioned laboratory.

During each exposure, the following parameters were recorded four times at about 1-hour intervals:
Temperatures: The temperatures in the inhalation system were measured continuously with a digital thermometer.
Humidity: The humidities in the inhalation system were measured with a dielectric probe (Testo).
Supply air flows (compressed air): 3.0 m³/h (test group 1), 1.5 m³/h (test groups 2 - 4); The flows were adjusted and continuously measured with
a flowmeter (rota).
Exhaust air flows: 3.2 m³/h (test group 1), 1.35 m³/h(test groups 2 - 4); The flows were adjusted and continuously measured with a flowmeter (rota).
- Test group 1:
The higher amounts of exhaust air, which were adjusted by means of a separate exhaust air system, achieved negative pressures inside the exposure system. This ensured that no contamination of the laboratory occurred owing to possible leakage from the inhalation chambers. Air changes of about 15 times per hour can be calculated by dividing the supply air flows by the volume of the inhalation systems. The animals were exposed to the inhalation atmosphere for 4 hours plus equilibration time of the inhalation systems (t99 about 20 min).
- Test groups 2 – 4:
The lower amounts of exhaust air, which were adjusted by means of a separate exhaust air system, achieved positive pressures inside the exposure systems. This ensured that the mixtures of test substance and air were not diluted with laboratory air in the breathing zones of the animals. Air changes of about 27 times per hour can be calculated by dividing the supply air flows by the volume of the inhalation systems. The animals were exposed to the inhalation atmosphere for 4 hours plus equilibration time of the inhalation systems (t99 about 10 min). No surveillance of the oxygen content in the inhalation system was performed. The air change was judged to be sufficient to prevent oxygen depletion by the breathing of the animals, and the concentration of the test substance used could not have a substantial influence on oxygen partial pressure.

ANALYSIS OF TEST ATMOSPHERES
- Nominal concentration: calculated from the amounts of substance dosed and the supply air flows.
- Actual concentration:
Analysis of the test substance concentrations was conducted at the Laboratory of Analytical Chemistry of the Experimental Toxicology and Ecology of BASF SE, using a gas chromatographic method with FID detection.
Sampling equipment and procedure:
Air sampler GS 312 (DESAGA); Sorption solvent: 2-Propanole.
Sampling devices: Sampling probe (diameter: 7 mm) with quartz wool plug (groups 1-4) and 3 fritted glass flasks connected in series and filled with sorption solvent (groups 1-2) or 3 impingers connected in series and filled with sorption solvent (groups 3-4).
The quartz wool plug and the content of the first two absorption vessels were pooled and analyzed for each sample. The third absorption vessel was used to control the effectiveness of the sorption for all samples of the atmosphere and was analyzed separately at the end of the sampling campaign.
Sampling position: immediately adjacent to the animals' noses
Sampling flow: 1 L/min (group 1), 3 L/min (groups 2 - 4)
Sampling velocity: 1.25 m/s
Sampling frequency: 4 samples at about hourly intervals
Sampling volumes: 30 L for groups 1 and 2, 15 L for group 3 and 6 L for group 4 (volumes were adjusted to achieve suitable amounts of the test substance in the samples in reference to the calibration of the analytical method).
- Particle size
Particle size distributions were only measured for groups 2 – 4.
Equipment: Stack Sampler Mark III (Andersen), Vacuum pump (Millipore), Sampling probe (internal diameter 6.9 mm), Limiting orifice 3 L/min. Before sampling, the impactor stages were assembled with collecting discs and equipped with a backup particle filter. The impactor was connected to the vacuum pump. 30 Minutes (or later) after initiation of exposure, samples were taken from the breathing zone of the animals (sample size: 30 L for group 2, 15 L for groups 3 and 4; one sample per concentration).
After sampling the impactor was taken apart. The impactor stages and the backup particle filter were eluted individually with solvent (2-Propanole). The samples were analyzed by the same GC-FID method as used for the actual test atmosphere concentrations. The amounts of material adsorbed to the walls of the impactor and in the sampling probe (wall losses) were also determined quantitatively.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

0.130, 0.408, 1.119,. 3.113 mg/L (actual concentrations)

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Observation period: 14 days
- Bodyweight determination: Individual body weights were recorded shortly before exposure, weekly thereafter and at the end of the study. Additionally, body weights were measured in animals that died or were sacrificed in a moribund state from study day 1 onward.
- Signs and symptoms: Detailed clinical observations were recorded for each rat separately several times during exposure and at least once on each working day of the observation period. No comprehensive clinical examination was performed on weekends or public holidays.
- Mortality: A check for dead or moribund animals was made twice each working day and once on weekends and public holidays.
- Pathology: At the end of the observation period the surviving animals were sacrificed with CO2-inhalation in a chamber with increasing concentration over time, and were subjected to gross-pathological examination as were the animals which had died or were killed in a moribund state before. To examine possible toxic effects of the test substance on the nerve system a histopathological (HE stain) immunohistochemical investigation (tyrosine hydroxylase-specific antibody) was carried out on brain samples of animals of the high concentration group. Each moribund animal, which most probably would have died on account of the toxic effects of the substance was killed during the observation period according to the German Animal Protection Law (BGBL I, Aug. 22, 1986).

Statistics:

Probit analysis for LC50

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1.881 mg/L air (analytical)

Based on:

test mat.

95% CL:

1.222 - 3.115

Exp. duration:

4 h

Remarks on result:

other: (liquid aerosol and vapour)

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

2.038 mg/L air (analytical)

Based on:

test mat.

95% CL:

0.829 - 10

Exp. duration:

4 h

Remarks on result:

other: (liquid aerosol and vapour), upper limit 95% confidence interval >10 mg/L

Effect levels 3

Sex:

female

Dose descriptor:

LC50

Effect level:

1.863 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: (liquid aerosol and vapour)

Mortality:

No mortalities occurred at 0.130 mg/L (68% vapour and 32% liquid aerosol) and at 0.408 mg/L (17% vapor and 83% liquid aerosol).
At 1.119 mg/L (6% vapour and 94% liquid aerosol) two of five males died during exposure but no females died.
At 3.113 mg/L (4% vapour and 96% liquid aerosol) all the female and three of the five male animals died or were sacrificed in a moribund state, either during exposure, after exposure on day 0 or on day 1.

Clinical signs:

other: - At 0.130 mg/L: visually increased respiration, abdominal respiration and piloerection. Findings were observed from hour 1 of exposure through to study day 2. No clinical signs and findings were observed from study day 5 onwards. - At 0.408 mg/L: visua

Body weight:

- At 0.130 mg/L and 0.408 mg/L, 1.119 mg/L: Mean body weights of the (surviving) animals increased throughout the study period.
- At 3.113 mg/L: Mean body weights of the surviving male animals decreased during the first post exposure observation week but increased during the second week.

Gross pathology:

- At 0.130 mg/L and 0.408 mg/L: No gross pathological abnormalities were noted during the necropsy at termination of the post exposure observation period.
- At 1.119 mg/L: Gross pathological abnormalities were neither noted in the male animals that died on day 0 nor in those sacrificed at termination of the post exposure observation period.
- At 3.113 mg/L: Necropsy findings of the male and female animals that died on day 0 showed no gross pathological abnormalities. In the female that died on day 1 several black erosions/ulcers of the glandular stomach were observed. No gross pathological abnormalities were noted in the two males sacrificed at termination of the post exposure observation period.

Other findings:

Immunohistochemistry for tyrosine hydroxylase (specific marker to reveal dopaminergic neurons and their synaptic end terminals) of all animals of the 3.113 mg/L group and of two control animals (1/sex) revealed no differences in the staining intensity in the nigrostriatal bundle and substantia nigra of brain sections. Further pathological changes (e.g. necrotic neurons) were not detected in this first and limited, morphological examination of brain levels.

Any other information on results incl. tables

Particle size distribution:

- Mass median aerodynamic diameter (MMAD): 1.8, 1.9 and 1.9 μm for groups 2, 3 and 4, respectively.

- Geometrical standard deviation: 2.3, 2.9 and 2.9 for groups 2, 3 and 4, respectively.