Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991-08-08 to 1991-08-22
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP guideline study reliable with restrictions Reason for RL- rating: according to Guidance on information requirements and chemical safety assessment Chapter R. 7a: Endpoint specific guidance, inhaled particles should have a MMAD between 1 and 4 microns. The MMAD in this study was slightly above the recommened value.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Version / remarks:
adopted 1981-05-12
Deviations:
yes
Remarks:
no vehicle control group was used; no acclimatisation period was stated; it was not stated if a dynamic air flow of 12 to 15 air changes per hour was used; no equilibrium period was stated; clinical observations only at least once on workday
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report): Sicocer F Eisenrosa 2320
- Physical state: solid (powder) / pink
- Storage condition of test material: was stored at room temperature
- Homogeneity: was guaranteed by high purity

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS - strain: SPF Wistar/Chbb:THOM
- Age at study initiation: approx. 8 - 9 weeks
- Weight at study initiation: males (mean): 284 +/- 4.3 g; females (mean): 203 +/- 8.0 g
- Housing: housed singly in cages type DK III of Becker, without bedding
- Diet (ad libitum during the post exposure period): KLIBA rat/mouse/hamster laboratory diet 24-343-4 10 mm pellets, Klingentalmühle AG, CH-4303 Kaiseraugst, Switzerland
- Water (ad libitum during the post exposure period): drinking water

ENVIRONMENTAL CONDITIONS - the animals were kept in fully air-conditioned rooms
- Temperature: 20 - 24 °C
- Relative humidity: 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose/head only
Vehicle:
other: Aerosil and clean air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: head-nose inhalation system INA 20 (glass-steel construction, BASF Aktiengesellsschaft, volume V ~55 L): the animals were restrained in tubes and their snouts projected into the inhalation chamber.

- Source and rate of air/method of conditioning air/treatment of exhaust air: the following air flow (supply air) was set: 1,500 L/h
The exposure system was placed in an air-conditioned laboratory.
By means of an exhaust air system the pressure ratios in the inhalation system were adjusted in such a way that the amount of exhaust air was about 10 % lower (excess pressure). This ensured that the mixture of test substance and air was not diluted with laboratory air in the breathing zones of the animals.

- System of generating particulates/aerosols: the aerosol was produced with a dosing -wheel dust generator (Gericke/BASF) and compressed air.
A glass cyclonic separator (BASF) was connected downstream with the generator.
The concentration was adjusted by varying the rotation of the metering disc.

- Method of particle size determination: 30 minutes after the beginning of the test at the earliest, one sample was taken per test group for the particle size analysis (equipment: Stack Sampler Mark III (Andersen), vacuum compressed air pump (Millipore), sampling probe (internal diameter 6.9 mm), balance (Sartorius M3P and Mettler AE 240), evaluation unit (IBM-PC with software PGA).
Before the sampling, the impactor was equipped with glass-fiber collecting discs and a backup particle filter. The impactor was connected to the pump and the test apparatus, and one sample (9 L) was taken.
The impactor was taken apart, and the collecting discs and the backup particle filter were weighed.
The contents of the pre-impactor as well as the amounts of the material adsorbed on the walls of the impactor and in the sampling probe (wall losses) were also determined quantitatively.

- Temperature and humidity: the humidity in the inhalation system was not measured due to technical reasons. It is assumed that deviations of humidity values from the guideline requirements (especially low humidity in dust aerosol) did not influence the test results, because of the relative short exposure time.
The temperature in the inhalation system was measured continuously and recorded once.

TEST ATMOSPHERE
- Nominal concentration: the nominal concentration was calculated from the amount of substance consumed and the air flow.

- Brief description of analytical method used:gravimetric determination of the inhalation atmosphere concentration (apparatus: vacuum compressed air pump (Millipore), filtration equipment with probe (internal diameter: 4 mm, (Millipore)), filter (MN 85/90 Bf (d = 4.7 cm), sampling velocity 1.25 m/s, sampling amount 2 L, sampling frequency 1 sample about hourly)(balance: Mettler AT 250)
The preweighed filter was placed into the filtration equipment. By means of a vacuum compressed air pump a volume of the dust aerosol was drawn through the filter.
The dust concentration in mg/L was calculated from the difference between the preweight of the filter and the weight of the filter after sampling, with reference to the sample volume of the inhalation atmosphere. The concentrations were corrected for the amount of the added excipient.
- Samples taken from breathing zone: yes

VEHICLE
- Justification of choice of vehicle: the test substance was mixed with 1% (w/w) of aerosil in order to achieve a more uniform dust concentration in air.

TEST ATMOSPHERE (if not tabulated)
- MMAD* (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): MMAD: 5.1 µm (GSD: 2.4)(respirability**: 85 %)
Inspite of several technical measures (mixing, addition of some additives, use of cyclonic separator) no smaller particle size could be reached
* the amounts of the material determined in the particle size analysis were not corrected for the additive
** respirable dust fraction that might reach the alveolar region, obtained from the results of the particle size analysis
Analytical verification of test atmosphere concentrations:
yes
Remarks:
please refer "details on inhalation exposure" above
Duration of exposure:
4 h
Concentrations:
Actual concentration: 5.6 +/- 0.30 mg/L
Nominal concentration: 53.8 mg/L
No. of animals per sex per dose:
5 males / 5 females
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: the body weight of the animals was checked before the beginning of the test, after 7 days and at the end of the observation period. Clinical findings were recorded for each animal separately several times during exposure and at least once each workday in the observation period (no clinical observations were performed on test days 2, 3, 9 and 10 (holiday or weekend; day 0 = post-exposure on exposure day). A check for dead animals was made daily.
- Necropsy of survivors performed: yes; at the end of the 14-day observation period the animals were sacrificed with CO2 and were subjected to gross-pathological examination.
Statistics:
The statistical evaluation of the dose-response relationship was carried out using FORTRAN program AKPROZ. Depending on the data of the dose-response relationship obtained by way of experiment, this program is used to estimate the LC50 or to perform a Probit analysis (see Finney, D.J. (1971): "Probit Analysis", Cambridge University Press). Estimation of the LC50 will produce types LC50 greater, LC50 about, or LC50 smaller. If results are Type LC50 greater or LC50 smaller, an additional binominal test is carried out (Witting, H. (1974): "Mathematical Statistik", B.G. Teubner, Stuttgart, pp. 32 -35.), in order to verify these statements statistically, if necessary.
The calculation of the particle size distribution was carried out in the Deparment of Toxicology of BASF Aktiengesellschaft on the basis of mathematical methods for evaluating particle measurements (DIN 66141: Darstellung von Korngrößenverteilungen, DIN 66151: Partikelgrößenanalyse (Beuth-Vertrieb GmbH, D-W1000 Berlin 30 and D-W5000 Köln 1).

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.6 mg/L air (analytical)
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: The statistical reliability is 99 %.
Mortality:
No mortality occurred at the limit concentration of 5.6 mg/L.
Clinical signs:
other: During exposure and in the post-exposure observation period: clinical examination showed irregular respiration (3/5 m; 5/5 f) and accelerated respiration (all animals) as well as attempts to escape during exposure (all animals). No clinical abnormalities
Body weight:
Body weight gain was not affected over the whole post exposure period.
Gross pathology:
No pathological findings were noted in sacrificed animals.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
LC50 (male and female rats; 4 hours) > 5.6 mg/L
According to the EC-Commission directive 67/548/EEC and its subsequent amendments, the test substance is not classified as acute toxic via the inhalation route.
According to the EC-Regulation 1272/2008 and subsequent regulations, the test item is not classified as acute toxic via the inhalation route.