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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
14.1.-3.3.2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was carried out in accordance with internationally valid GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Deviations:
no
GLP compliance:
yes (incl. certificate)
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Fluidized Bed Combustioin (FBC) Fly Ash
- Physical state: pale grey solid
- Lot/batch No.: FBC/230309/T1
- Expiration date of the lot/batch: 24.3.2024
- Storage condition of test material: Room temperature, in the dark

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Ltd, Oxon, UK
- Age at study initiation: 9-12 weeks
- Weight at study initiation: 200-350 g
- Housing: solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes and provided with environmental enrichment items: wooden chew blocks and cardboard “fun tunnels”
- Diet and water (e.g. ad libitum): free access to mains drinking water and food, with the exception of the exposure period
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 °C
- Humidity (%): 30-70 %
- Air changes (per hr): at least 15 changes per hour
- Photoperiod (hrs dark / hrs light): 12 hrs continuous light / 12 hrs darkness

IN-LIFE DATES: From: 3.2. 2010 To: 10.2. 2010

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose only
Vehicle:
clean air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: the cylindrical exposure chamber
- Exposure chamber volume: approximately 30 L
- Method of holding animals in test chamber: a tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber and sealed by means of a rubber ‘O’ ring
- Source and rate of air: Compressed air was supplied by means of an oil free compressor. Air flow during exposure 40 L/min.
- Method of conditioning air: Compressed air was passed through a water trap and respiratory quality filters.
- System of generating particulates/aerosols: A dust atmosphere was produced using a SAG 410 Solid Aerosol Generator located adjacent to the exposure chamber. The SAG 410 was connected to a metered compressed air supply.
- Method of particle size determination: The particle size of the generated atmosphere inside the exposure chamber was determined three times during the exposure period using a Marple Personal Cascade Impactor
- 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.
- Temperature, humidity, pressure in air chamber: The temperature and relative humidity inside the exposure 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 thirty
minutes throughout the four-hour exposure period. The chamber was maintained under negative pressure.

TEST ATMOSPHERE
- Brief description of analytical method used: 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 the 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.
- Samples taken from breathing zone: yes

- Particle size distribution: See Table in "Any other information on results"
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 3.71 µm / 3.42

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: GHS Classification System (5 mg/L)
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
Mean achieved atmosphere concentration: 5.38 mg/L
Nominal concentration: 28.7 mg/L
No. of animals per sex per dose:
5 animals/dose/sex
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 fourteen days. Individual bodyweights were recorded prior to treatment on the day of exposure and on Days 7 and 14.
- Necropsy of survivors performed: yes

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.38 mg/L air
Based on:
test mat.
Exp. duration:
4 h
Mortality:
No deaths occured.
Clinical signs:
other: Common abnormalities noted during the study included increased respiratory rate, hunched posture, pilo-erection and wet fur. There were occasional instances of noisy respiration and isolated instances of decreased respiratory rate, laboured respiration an
Body weight:
Two male animals exhibited a reduced bodyweight gain or slight bodyweight loss during Week 1, both recovered to show normal development during
Week 2. One female animal exhibited a slight bodyweight loss during Week 2. Normal bodyweight development was noted for all other animals during the course of the study.
Gross pathology:
No macroscopic abnormalities were detected at necropsy.

Any other information on results incl. tables

Table: Particle Size Distribution - Calculation

 

Cut point (µm)

Mean Cumulative Amount Less Than Cut Point

(mg)

%

Probit

9.0

2.12

83.1

5.96

6.3

1.66

65.1

5.39

4.0

1.06

41.6

4.79

1.7

0.62

24.3

4.30

0.81

0.25

9.80

3.71

0.30

0.08

3.14

3.14

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 a mean achieved atmosphere concentration of 5.38 mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of Fluidized Bed Combustion (FBC) Fly Ash, in the HsdHanTM : WIST strain rat, was greater than 5.38 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” referenced as Method B2 (Inhalation) of Commission Regulation (EC) No. 440/2008.

 

Methods. A group of ten HsdHanTM : WIST 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.

Mean achieved atmosphere concentration:

Mean achieved atmosphere concentration (mg/L) = 5.38

Standard deviation = 1.41

Nominal concentration: 28.7 mg/L

 

The characteristics of the achieved atmosphere:

Mean Mass Median Aerodynamic Diameter (MMAD) = 3.71 μm

Geometric Standard Deviation (GSD) = 3.42

Predicted amount less than 4 μm = 52.5%

 

The mortality data:

Male: 0/5

Female: 0/5

Total: 0/5

 

Conclusion. No deaths occurred in a group of ten rats exposed to a mean achieved atmosphere concentration of 5.38 mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of Fluidized Bed Combustion (FBC) Fly Ash, in the HsdHanTM : WIST strain rat, was greater than 5.38 mg/L.