2,4,8,10-Tetraoxaspiro[5.5]undecane-3,9-diethanol, .beta.3,.beta.3,.beta.9,.beta.9-tetramethyl-

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007-07-27 to 2007-09-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test was performed according to guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

485-230-3

EC Name:

-

Cas Number:

1455-42-1

Molecular formula:

Hill formula: C15H28O6 CAS formula: C15H28O6

IUPAC Name:

2-[9-(1-hydroxy-2-methylpropan-2-yl)-2,4,8,10-tetraoxaspiro[5.5]undecan-3-yl]-2-methylpropan-1-ol

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): SPG
- Physical state: White powder
- Lot/batch No.: 50908-02
- Storage condition of test material: Room temperature in the dark

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 (UK) Ltd, Margate, Kent.
- Age at study initiation: Approximately 8 to 12 weeks old.
- Weight at study initiation: within the range of 200 g to 350 g.
- Fasting period before study: No.
- Housing: The animals were housed in groups of five by sex in solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes.
- Diet (e.g. ad libitum): With the exception of the exposure period, free access to food (EU Rodent Diet 5LF2, BCM IPS Ltd, London, UK) was allowed throughout the study.
- Water (e.g. ad libitum): With the exception of the exposure period, free access to mains drinking water was allowed throughout the study.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25 °C
- Humidity (%): 30 - 70 % relative humidity.
- Air changes (per hr): At least 15 air changes per hour.
- Photoperiod (hrs dark / hrs light): Twelve hours continuous light and 12 hours continuous darkness.

IN-LIFE DATES: From: Day 1 To: Day 14

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

other: Compressed air from an oil free compressor and passed through a water trap and respiratory quality filters before passing through a SAG 410 Solid Aerosol Generator

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Cylindrical exposure chamber
- Exposure chamber volume: Approximately 30 L (dimensions: 28 cm diameter x 50 cm high).
- Method of holding animals in test chamber: Each rat was individually held in a tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber and sealed by means of a rubber “O” ring. Only the nose of each animal was exposed of the test atmosphere.
- Source and rate of air: The SAG 410 was connected to a metered compressed air supply.
- Method of conditioning air: Compressed air was supplied by means of an oil-free compressor and passed through a water trap and respiratory quality filters before it was introduced to the SAG 410.
- System of generating particulates/aerosols: A dust atmosphere was produced from the test material using a SAG 410 Solid Aerosol located adjacent to the exposure chamber. The concentration within the chamber was controlled by adjusting the test material feed rate form the SAG 410.
- Treatment of exhaust air: The extract from the exposure chamber passed through a “scrubber” trap and was connected with a high efficiency filter to a metered exhaust system. The chamber was maintained under negative pressure.
- Temperature, humidity, pressure in air chamber: The temperature and relative humidity inside the chamber were measured by an electronic thermometer/humidity meter located in a vacant port in the animals’ breathing zone of the chamber and recorded every 30 minutes throughout the four-hour exposure period. Oxygen levels within the exposure chamber were measured by an electronic oxygen analyser located in a sampling port in the animals’ breathing zone during the four-hour exposure period. The test atmosphere was generated to contain at least 19 % oxygen.

VEHICLE
No vehicle used.

TEST ATMOSPHERE
Homogeneity of the test atmosphere within the chamber was not specifically determined during the study. Chambers of the same design have been fully validated and shown to produce evenly distributed atmospheres in the animals’ breathing zone with a wide variety of materials tested. Prior to the start of the study, test material atmospheres were generated within the exposure chamber. During this characterisation period test material input rates were varied to achieve the required atmospheric concentrations.
The actual chamber concentration was measured at regular intervals during the exposure period. The gravimetric method used glass fibre filters placed in a filter holder. The holder was temporarily sealed in a vacant port in the exposure chamber in the animals’ breathing zone and a suitable, known volume of exposure chamber air was drawn through the filter using a vacuum pump. Each filter was weighed before and after sampling in order to calculate the weight of collected test material. The difference in the two weights, divided by volume of atmosphere sampled, gave the actual chamber concentration. The nominal chamber concentration was calculated by dividing the mass of test material used by the total volume of air passed through the chamber.
- Particle size distribution:
The particle size of the generated atmosphere inside the exposure chamber was determined three times during the exposure period using a Maple Personal Cascade Impactor. This device consisted of six impactor stages (9.4, 6.2, 3.6, 1.5, 0.71 and 0.32 µm cut points) with stainless steel collection substrates and a back up glass fibre filter housed in an aluminium sampler. The sampler was temporarily sealed in a sampling port in the animals’ breathing zone and a suitable, known volume of exposure chamber air was drawn through it using a vacuum pump.
The collection substrates and backup filter were weighed before and after sampling and the weight of test material, collected at each stage, calculated by difference.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):
The mean amount for each stage was used to determine the cumulative amount below each cut-off point size. In this way, the proportion (%) of aerosol less than 9.4, 6.2, 3.6, 1.5, 0.71 and 0.32 µm was calculated. The resulting values were converted to probits and plotted against log10 cut-point size. From this plot, the Mean Mass Aerodynamic Diameter (MMAD) was determined (as the 50 % point) and the geometric standard deviation was calculated. In addition, the proportion (%) of aerosol less than 4 µm (considered to be the inhalable fraction) was determined.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetric method; glass fibre filters

Duration of exposure:

4 h

Concentrations:

The target concentration was 5 mg/L.

No. of animals per sex per dose:

5 per sex per dose.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing: All animals were observed for clinical signs at hourly intervals during exposure, immediately on removal from the restraining tubes at the end of exposure, one hour after termination of exposure and subsequently once daily for 14 days. Any overt evidence of toxicity was recorded at each observation.
Individual bodyweights were recorded prior to treatment on the day of exposure and on Days 7 and 14.
- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical signs and bodyweight.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.98 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Based on the mean achieved atmosphere concentration.

Mortality:

There were no deaths during the study period.

Clinical signs:

other: Signs of hunched posture and pilo-erection are commonly seen in animals for short periods on removal from the chamber following 4-h inhalation studies. Wet fur is commonly recorded both during and for a short period after exposure. These observations are

Body weight:

Variations in bodyweight gain are frequently seen for female animals of this strain and age during this type of study and, in isolation, are considered not to be significant.
Normal body weight development was noted during the study.

Gross pathology:

No macroscopic abnormalities were detected amongst six animals at necropsy.
The following macroscopic abnormalities were detected amongst the other animals at necropsy:
Lungs - abnormally red, with dark patches, or pale patches.

Other findings:

Exposure chamber concentration
The test atmosphere was sampled 19 times during the exposure period and the actual concentration of the test material calculated. The mean values obtained were:
Mean achieved: 4.98 mg/L
Standard deviation: 0.85
Nominal: 9.72 mg/L

The chamber flow-rate was maintained at 50L/min providing 100 air changes per hour.

The theoretical chamber equilibration time (T99) was 3 minutes (Silver, 1946).

Particle size distribution
The particle size analysis of the atmosphere drawn from the animal's breathing zone was as follows:
Mean achieved atmospheric concentration: 4.98 mg/L
MMAD: 1.78 µm
Inhalable fraction: 75 % < 4 µm
Geometric standard deviation: 3.33

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

No deaths occurred in a group of ten rats exposed to mean achieved atmosphere concentration of 4.98 mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of SPG in the Sprague-Dawley Crl:CD (SD) IGS BR strain rat was greater than 4.98 mg/L.

Executive summary:

Introduction.

A study was performed to assess the acute inhalation toxicity of the test material. The method used followed that described in the OECD Guidelines for Testing of Chemicals (1981) no. 403 “Acute Inhalation Toxicity” references as Method B2 in Commission Directive 92/69/EEC “Acute Toxicity – Inhalation” (which constitutes Annex V of Council Directive 67/548/EEC).

Methods.

A group of ten Sprague-Dawley Crl:CD (SD)IGS BR strain rats (five males and five females) was exposed to a dust atmosphere. The animals were exposed for four hours using a nose-only exposure system, followed by a fourteen day observation period.

Results.

The mean achieved atmosphere concentration was:

Mean achieved: 4.98 mg/L

Standard deviation: 0.85

Nominal: 9.72 mg/L

The characteristics of the achieved atmosphere were as follows;

Mean achieved atmospheric concentration: 4.98 mg/L

MMAD: 1.78 µm

Inhalable fraction: 75 % < 4 µm

Geometric standard deviation: 3.33

Mortality: There were no deaths.

Clinical observations: Common abnormalities noted during the study included increased respiratory rate, hunched posture, pilo-erection and wet fur. There were frequent instances of laboured respiration and isolated occurrences of decreased respiratory rate and noisy respiration. Animals recovered quickly to appear normal from Days 2 to 3 post-exposure.

Bodyweight: Normal bodyweight development was noted during the study.

Necropsy: No macroscopic abnormalities were detected amongst six animals at necropsy. The following macroscopic abnormalities were detected amongst the other animals at necropsy: Lungs – abnormally red with/without dark patches, or pale patches.

Conclusion.

No deaths occurred in a group of ten rats exposed to a mean achieved atmosphere concentration of 4.98 mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 h LC50) of the test substance in the Sprague-Dawley Crl:CD (SD) IGS BR strain rat, was greater than 4.98 mg/L.