Slags, sponge iron production by coal reduction in retort

Endpoint summary

Description of key information

No acute toxicity of any slag

Basis for this conclusion

Oral

The acute oral toxicity of the test material was assessed in accordance with OECD Guideline 420.  The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was considered to be greater than 2000 mg/kg body weight.  Therefore, the test material does not meet the criteria for classification.  

Inhalation

GGBS: OECD 403, rats: 4 h-LC50 >5235 mg/m3

In accordance with the CLP Regulation, industrial minerals producers have conducted a Review and Hazard Assessment of the health effects of respirable crystalline silica and have jointly determined it best and appropriate to classify crystalline silica (fine fraction) (quartz (fine fraction) and cristobalite (fine fraction)) as STOT RE 1 for the silicosis hazard. This is because particles of crystalline silica (fine fraction) may become airborne during handling and use in the workplace, creating respirable crystalline silica (RCS).

STOT refers to Specific Target Organ Toxicity. RE refers to “Repeated Exposure”. Based upon scientific evidence, it is generally necessary to inhale significant quantities of RCS in an occupational setting for prolonged and repeated periods of time before any possible long-term health effect may occur.

This classification applies to the fine fraction of quartz and cristobalite only, because it is scientifically demonstrated that it is only this fraction of crystalline silica, when made airborne, which may cause health effects. It is also in compliance with the CLP Regulation which allows consideration of the physical form(s) or physical state(s) of substance or mixture.

As a consequence of this classification, mixtures and substances containing crystalline silica (fine fraction), whether in the form of an identified impurity, additive or individual constituent, are classified as:

STOT RE 1, if the crystalline silica (fine fraction) concentration is equal to, or greater than 10%;

STOT RE 2, if the crystalline silica (fine fraction) concentration is between 1 and 10%.

If the crystalline silica (fine fraction) content in mixtures and substances is below 1%, no classification is required.

Therefore, no classification for this substance is required

Skin

BOS, SMS: rats OECD 402, rats: LD50 > 4000 mg/kg

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 July 2015 to 04 August 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

ANIMALS and ANIMAL HUSBANDRY
- Female Wistar rats were supplied by Envigo RMS (UK) Ltd, Oxon, UK.
- The animals were randomly allocated to cages on receipt.
- Females were nulliparous and non-pregnant.
- After an acclimatisation period of at least 5 days the animals were selected at random and given a unique number within the study by indelible ink-marking on the tail and the number was written on a cage card.
- At the start of the study the animals were 8 to 12 weeks of age.
- Body weight did not exceed ± 20 % of the mean body weight at the start of treatment.
- Animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes.
- With the exception of an overnight fast immediately before dosing, and for approximately 3 to 4 hours after dosing, free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Envigo Research (UK) Ltd, Oxon, UK was allowed throughout the study.
- Diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that would reasonably be expected to affect purpose or integrity of the study.
- Temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70 % respectively.
- Rate of air exchange was at least 15 changes per hour.
- Lighting was controlled by a time switch to give 12 hours continuous light (06:00 to 18:00) and 12 hours darkness.
- Animals were provided with environmental enrichment items considered not to contain any contaminant at a level that might affect the purpose or integrity of the study.

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

TEST ITEM FORMULATION and EXPERIMENTAL PREPARATION
- For the purpose of the study, the test item was freshly prepared, as required, as a suspension in arachis oil BP. Arachis oil was chosen because the test material did not dissolve or suspend in distilled water.
- The test item was formulated within 2 hours of being applied to the test system and it was assumed that the formulation was stable for that duration.
- No analysis was conducted to determine the homogeneity, concentration or stability of the test item formulation. This is an exception with regard to GLP and was reflected in the GLP compliance statement.

Doses:

- 300mg/kg (concentration 30mg/mL; dose volume 10mL/kg) - 1 animal
- 2000 mg/kg (concentration 20mg/mL; dose volume 10 mL/kg) - 5 amimals

No. of animals per sex per dose:

- In the absence of available data a single female animal dosed at 300 mg/kg
- In the absence of toxicity, a single female animal dosed at 2000 mg/kg
- In the absence of toxicity at the dose level of 300mg/kg, an additional group of four female animals dosed at 2000 mg/kg

Control animals:

no

Details on study design:

- All animals were dosed once by gavage using a metal cannula attached to a graduated syringe.
- The volume administered to each animal was calculated according to the fasted body weight at the time of dosing.
- Treatment of animals was sequential.
- Sufficient time was allowed between each dose level to confirm the survival of the previously dosed animals.
- Clinical observations were made 0.5, 1, 2 and 4 hours after dosing and then daily for 14 days.
- Morbidity and motality checks were made twice daily.
- Individual body weights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
- Animals were killed by cervical dislocation at the end of the observation period.
- All animals were subjected to gross necropsy consisting of external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded but no tissues were retained.

Preliminary study:

DOSE LEVEL 300 mg/kg
- There was no mortality.
- No signs of systemic toxicity were noted during the observation period.
- The animal showed expected gains in body weight over the observation period.
- No abnormalities were noted at necropsy.

DOSE LEVEL 2000 mg/kg
- There was no mortality.
- No signs of systemic toxicity were noted during the observation period.
- The animal showed expected gains in body weight over the observation period.
- No abnormalities were noted at necropsy.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

- There were no deaths

Clinical signs:

other: No signs of systemic toxicity were noted during the observation period

Gross pathology:

- No abnormalities were noted at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral toxicity of the test material was assessed in accordance with OECD Guideline 420. The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was considered to be greater than 2000 mg/kg body weight. Therefore, the test material does not meet the GHS criteria for classification.

Executive summary:

GUIDELINE

The study was designed to be compatible with OECD Guideline for Testing of Chemicals No 420 "Acute Oral Toxicity - Fixed Dose Method" (2001) and Method B1 bis Acute Toxicity (Oral) of Commission Regulation (EC) No 440/2008.

METHOD

Following a sighting test at a dose level of 300 mg/kg & 2000mg/kg , a further group of four fasted female animals were given a single oral dose of the test item as a suspension in arachis oil BP at a dose level of 2000 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

RESULTS

- Mortality: There were no deaths.

- Clinical observations:There were no signs of systemic toxicity.

- Body weight: All animals showed expected gains in body weight.

- Necropsy: No abnormalities were noted at necropsy.

CONCLUSION

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was considered to be greater than 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start date: 06 February 2018, Experimental completion date: 08 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

yes

Remarks:

Please see "Principles of method if other than guideline" for further details.

Qualifier:

according to guideline

Guideline:

EU Method B.52 (Acute Inhalation Toxicity - Acute Toxic Class Method)

Deviations:

yes

Remarks:

Please see "Principles of method if other than guideline" for further details.

Principles of method if other than guideline:

The following deviation from study plan occurred:
Deviation No 1
The relative humidity within the exposure chamber during the exposures was found to be lower than the range specified in the inhalation test guidelines (30 70 %). The decreased humidity was considered to be unavoidable due to the effect of the test item on the humidity.
This deviation is considered to have not affected the integrity or validity of the study.

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Male and female RccHan™ : WIST strain rats were supplied by Envigo RMS (UK) Limited, Oxon, UK. On receipt the animals were randomly allocated to cages. After an acclimatization period of at least 5 days the animals were given a number unique within the study by ear punching and a number written on a color coded cage card. At the start of the study the animals were approximately 8 to 12 weeks old and within the weight range of 200 g to 350 g. The females were nulliparous and non pregnant.
The animals were housed in groups of up to three by sex in solid floor polypropylene cages with stainless steel lids, furnished with softwood flakes. With the exception of the exposure period, free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Envigo RMS (UK) Limited, Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analyzed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.
- Fasting period before study:

ENVIRONMENTAL CONDITIONS
The temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness. The animals were retained in this accommodation at all times except during the exposure period.
The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

3.76 µm

Geometric standard deviation (GSD):

2.92

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
Prior to the start of the study, test item atmospheres were generated within the exposure chamber. During this characterization period test item input rates were varied in an attempt to achieve the required atmospheric conditions.
A dust atmosphere was produced from the test item using a SAG 410 Solid Aerosol Generator (TOPAS GmbH, Dresden, Germany) located adjacent to the exposure chamber. The SAG 410 was connected to a metered compressed air supply.
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.
The cylindrical exposure chamber had a volume of approximately 30 liters (dimensions: 28 cm diameter x 50 cm high). The concentration within the chamber was controlled by adjusting the test item feed rate from the SAG 410.
During the exposure period, 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 to the test atmosphere.
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.
The temperature and relative humidity inside the exposure chamber were measured by an electronic thermometer/humidity meter (Hanna Instruments Ltd, Beds., UK) located in a vacant port in the animals’ breathing zone of the chamber and recorded every 30 minutes throughout the 4 Hour exposure period.
Oxygen levels within the exposure chamber were measured by an electronic oxygen analyzer (Servomex (UK) Ltd, Crowborough, East Sussex) located in a port in the animals breathing zone during the 4 Hour exposure period. The test atmosphere was generated to contain at least 19% oxygen.

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 (Westech IS Ltd, Beds., UK). This device consisted of six impactor stages (10.4, 7.7, 4.1, 1.3, 0.9 and 0.56 µm cut points) with stainless steel collection substrates and a backup glass fiber filter, housed in an aluminum 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 item, collected at each stage, calculated by difference.
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 10.4, 7.7, 4.1, 1.3, 0.9 and 0.56 µm µm was calculated.
The resulting values were converted to probits and plotted against Log10 cut point size. From this plot, the Mass Median Aerodynamic Diameter (MMAD) was determined (as the 50% point) and the geometric standard deviation was calculated. In addition the proportion (percentage) of aerosol less than 4 µm (considered to be the inhalable fraction) was determined.

TEST ATMOSPHERE
The actual chamber concentration was measured at regular intervals during the exposure period. The gravimetric method used glass fiber 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 item. 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 item disseminated into the chamber by the total volume of air that flowed through the chamber during the exposure.

TEST ATMOSPHERE
Homogeneity of the test atmosphere within the chamber was not specifically determined during this study. Chambers of the same design (ADG Developments Ltd, Hitchin, Herts, UK) have been fully validated and shown to produce evenly distributed atmospheres in the animals’ breathing zone with a wide variety of test items (Green J D et al, 1984).

CLASS METHOD
As insufficient data was available on the expected inhalation toxicity of the test item, a sighting test was performed to determine the initial exposure concentration. A group of two animals (one male and one female) was exposed to an aerosol atmosphere of the test item at a target concentration of 2.0 mg/L.
Based on the results of the sighting test, a limit test was performed. A group of six animals (three males and three females) was exposed to an aerosol atmosphere of the test item at a target concentration of 5.0 mg/L.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Remarks on duration:

Following an appropriate equilibration period each group was exposed to an atmosphere of the test item for a period of 4 hours.

Concentrations:

5.07 mg/L

No. of animals per sex per dose:

3 male, 3 female

Control animals:

no

Details on study design:

All animals were observed for clinical signs at hourly intervals during exposure, immediately on removal from the restraining tubes at the end of exposure, 1 hour after termination of exposure and subsequently once daily for 14 days. Any evidence of overt toxicity was recorded at each observation.
Individual body weights were recorded on arrival, prior to treatment on the day of exposure (Day 0) and on Days 1, 3, 7 and 14.
At the end of the 14 observation period all animals were killed by intravenous overdose of sodium pentobarbitone. All animals were subjected to a full external and internal examination and any macroscopic abnormalities were recorded. The respiratory tract was subjected to a detailed macroscopic examination for signs of irritancy or local toxicity.

Preliminary study:

During exposure both animals exhibited decreased respiratory rate and wet fur. On removal from the chamber both animals exhibited decreased respiratory rate, labored respiration, hunched posture, fur stained dark grey by test item and wet fur. One hour post-exposure labored respiration was no longer present. No significant abnormalities were noted on Day 1 post-exposure. Both animals showed body weight loss on Day 1 post exposure and expected gains in body weight from Days 1 to 3. The female showed body weight loss and the male showed expected gains in body weight from Days 3 to 6 post-exposure.The following macroscopic abnormalities were detected at necropsy:
Lungs - Dark patches.
The observed abnormalities were potentially due to irritancy or local toxicity; however this was not confirmed by histopathological examination. It is also possible that the observations were caused by a residue, or deposition, of the test item. As a mean achieved atmosphere concentration of 2.02 mg/L was tolerated in the sighting test a target concentration of 5.0 mg/L was selected for the limit test.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

5.07 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

There were no deaths noted.

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-hour inhalation studies. Wet fur is commonly recorded both during and for a short period after exposure and staining of anima

Body weight:

All animals showed body weight loss on Day 1 post-exposure. With the exception of one female that showed body weight loss from Days 1 to 3 post-exposure all animals showed expected gains in body weight during the remainder of the recovery period.

Gross pathology:

The following macroscopic abnormalities were detected at necropsy:
Lungs – Pale, abnormally red, dark patches.
No macroscopic abnormalities were detected in one animal.
The observed abnormalities were potentially due to irritancy or local toxicity; however this was not confirmed by histopathological examination. It is also possible that the observations were caused by a residue, or deposition, of the test item.

Nominal Concentration

Comparison of the nominal and the actual concentration gives an indication of the generation efficiency of the of the test system. A lower value is considered to indicate a higher efficiency and values above 1000% are considered to indicate a highly inefficient test system. The nominal concentration in comparison to the actual concentration shows that the test system was highly inefficient during the exposure.

1645% of the actual mean achieved atmosphere concentration.

Exposure Chamber Concentration

The test atmosphere was sampled nine times during the exposure period and the actual concentration of the test item calculated. The mean values obtained were as follows:

Group Number	Atmosphere Concentration
	Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
1	5.07	0.18	83.39

The chamber flow rate was maintained at 40 L/min providing 80 air changes per hour.

The theoretical chamber equilibration time (T₉₉) was 4 minutes*(Silver, 1946).

* =  The test atmosphere was generated for 20 minutes prior to animal insertion to ensure test item concentration was being achieved

Particle Size Distribution

The particle size analysis of the atmosphere drawn from the animals’ breathing zone was as follows:

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Inhalable Fraction (% <4 µm)	Geometric Standard Deviation
1	5.07	3.76	52.3	2.92

Interpretation of results:

GHS criteria not met

Conclusions:

None of the animals died in a group of six rats exposed to mean achieved atmosphere concentration of 5.07 mg/L. It was therefore considered that the acute inhalation median lethal concentration (4 hour LC50) of the test item in the Wistar strain rat was greater than 5.07 mg/L.
The test item does not meet the criteria for classification according to Regulation (EC) No. 1272/2008, relating to the Classification, Labelling and Packaging of Substances and Mixtures.
The test item does not meet the criteria for classification according to the Globally Harmonized System of Classification and Labelling of Chemicals.

Executive summary:

Introduction

A study was performed to assess the acute inhalation toxicity of the test item. The method used was designed to be compatible with that described in the OECD Guideline for

Testing of Chemicals (2009) No. 436 “Acute Inhalation Toxicity – Acute Toxic Class Method” and Method B.52. Acute Inhalation Toxicity – Acute Toxic Class Method, 2014, of Commission Regulation (EC) No. 440/2008.

Methods

As insufficient data was available on the expected inhalation toxicity of the test item, a sighting test was performed to determine the initial exposure concentration. A group of two animals (one male and one female) was exposed to an aerosol atmosphere of the test item at a target concentration of 2.0 mg/L.

Based on the results of the sighting test, a limit test was performed. A group of six animals (three males and three females) was exposed to an aerosol atmosphere of the test item at a target concentration of 5.0 mg/L.

RccHan^TM: WIST strain rats were exposed for 4 hours using a nose only exposure system followed by an observation period. The observation period was six days for the sighting test, sufficient to ensure recovery of the animals, and fourteen days for the limit test.

Results

The mean achieved atmosphere concentration was as follows:

Group Number	Atmosphere Concentration
	Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
Sighting	2.02	0.07	30.70
1	5.07	0.18	83.39

The characteristics of the achieved atmosphere were as follows:

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Inhalable Fraction (% <4 µm)	Geometric Standard Deviation
Sighting	2.02	3.33	56.7	3.01
1	5.07	3.76	52.3	2.92

The mortality data were summarized as follows:

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Deaths
		Male	Female	Total
Sighting	2.02	0/1	0/1	0/2
1	5.07	0/3	0/3	0/6

Clinical Observations. Sighting: Common abnormalities noted during the study included decreased respiratory rate, labored respiration, hunched posture, pilo-erection, wet fur and fur stained dark grey by test item. No significant abnormalities were noted on Day 1 post‑exposure. 

Group 1: Common abnormalities noted during the study included decreased respiratory rate, hunched posture, pilo-erection, wet fur, fur stained black or dark grey by test item and tail stained black by test item. No significant abnormalities were noted on Day 2 post-exposure. Black colored tail was noted in all animals on Days 5 to 7 post‑exposure and fur stained dark grey by test item was apparent in all animals up to  Day 10 post-exposure, persisting in all males up to Day 13 post-exposure.

Body Weight. Sighting: Both animals showed body weight loss on Day 1 post-exposure and the female showed body weight loss from Days 3 to 6 post-exposure. Expected gains in body weight were noted during the remainder of the recovery period.

Group 1: All animals showed body weight loss on Day 1 post-exposure. With the exception of one female that showed body weight loss from Days 1 to 3 post-exposure all animals showed expected gains in body weight during the remainder of the recovery period. 

Necropsy. Sighting: The following macroscopic abnormalities were detected at necropsy:

Lungs – Dark patches.

Group 1:The following macroscopic abnormalities were detected at necropsy:

Lungs – Pale, abnormally red, dark patches.

No macroscopic abnormalities were detected in one animal.

The observed abnormalities were potentially due to irritancy or local toxicity; however this was not confirmed by histopathological examination.

Conclusion

None of the animals died in a group of six rats exposed to mean achieved atmosphere concentration of 5.07mg/L. It was therefore considered that the acute inhalation median lethal concentration (4 hour LC50) of the test item in the Wistar strain rat was greater than 5.07mg/L.

The test item does not meet the criteria for classification according to Regulation (EC) No. 1272/2008, relating to the Classification, Labelling and Packaging of Substances and Mixtures.

The test item does not meet the criteria for classification according to the Globally Harmonized System of Classification and Labelling of Chemicals.

Reference 2

Endpoint:

acute toxicity: inhalation

Remarks:

CS SWeRF

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

DATE SAMPLES RECEIVED: 23.10.17 DATE SAMPLES ANALYSED: 25.10.17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: Powder samples are analysed by laser diffraction

Version / remarks:

Powder samples are analysed by laser diffraction using the internal method SOP-017 “Particle Size Distribution by Laser Diffraction”. The technique for laser diffraction analysis is adopted from ISO 13320:2009 “Particle size analysis – Laser diffraction methods”.

Deviations:

no

Principles of method if other than guideline:

Quantification of any crystalline silica detected in the samples is carried out using an in-house method based on reference standards, drift correction and a calibration for calculating unknown concentrations.

GLP compliance:

not specified

Remarks:

Laser scattering/diffraction

Test type:

other: Portions of sieved samples are finely ground to create samples of uniform particle size

Limit test:

no

Details on test animals or test system and environmental conditions:

N/A

Key result

Sex:

not specified

Dose descriptor:

other: SWeRF Petrit T Lot 17100300

Effect level:

ca. 0 other: SWeRF Cryst. Silica (%)

Remarks on result:

other: Calculation of SWeRF from a Particle Size Distribution

Remarks:

The probability of a particle reaching the alveoli region of the lung is a function of its aerodynamic size (Dae) and the probability specified in the EN481 standard1. The principle behind SWeRF combines the particle size (determined by laser diffraction) and the probability factor, integrated across the complete particle size distribution. It is important to recognise that the EN481 probability is based on aerodynamic size as opposed to the spherical equivalent diameter measured by laser diffraction techniques A size weighting is then applied based on the probability function given in EN481 and expressed as a SWeRF percentage of the bulk. The methodology employed for the calculation of SWeRF is derived from “SWeRF – A Method for Estimating the Relevant Fine Fraction in Bulk Materials for Classification and Labelling Purposes

Key result

Sex:

not specified

Dose descriptor:

other: SWeRF Petrit T Lot 17100406

Effect level:

ca. 0.1 other: SWeRF Cryst. Silica (%)

Remarks on result:

other: Calculation of SWeRF from a Particle Size Distribution

Remarks:

The probability of a particle reaching the alveoli region of the lung is a function of its aerodynamic size (Dae) and the probability specified in the EN481 standard1. The principle behind SWeRF combines the particle size (determined by laser diffraction) and the probability factor, integrated across the complete particle size distribution. It is important to recognise that the EN481 probability is based on aerodynamic size as opposed to the spherical equivalent diameter measured by laser diffraction techniques A size weighting is then applied based on the probability function given in EN481 and expressed as a SWeRF percentage of the bulk. The methodology employed for the calculation of SWeRF is derived from “SWeRF – A Method for Estimating the Relevant Fine Fraction in Bulk Materials for Classification and Labelling Purposes

Key result

Sex:

not specified

Dose descriptor:

other: SWeRF Petrit T Lot 17100411

Effect level:

ca. 0.1 other: SWeRF Cryst. Silica (%)

Remarks on result:

other: Calculation of SWeRF from a Particle Size Distribution

Remarks:

The probability of a particle reaching the alveoli region of the lung is a function of its aerodynamic size (Dae) and the probability specified in the EN481 standard1. The principle behind SWeRF combines the particle size (determined by laser diffraction) and the probability factor, integrated across the complete particle size distribution. It is important to recognise that the EN481 probability is based on aerodynamic size as opposed to the spherical equivalent diameter measured by laser diffraction techniques A size weighting is then applied based on the probability function given in EN481 and expressed as a SWeRF percentage of the bulk. The methodology employed for the calculation of SWeRF is derived from “SWeRF – A Method for Estimating the Relevant Fine Fraction in Bulk Materials for Classification and Labelling Purposes

Key result

Sex:

not specified

Dose descriptor:

other: SWeRF Petrit T Lot 17100300

Effect level:

ca. 2.7 other: SWeRF Bulk Powder (%)

Remarks on result:

other: Calculation of SWeRF from a Particle Size Distribution

Remarks:

The probability of a particle reaching the alveoli region of the lung is a function of its aerodynamic size (Dae) and the probability specified in the EN481 standard1. The principle behind SWeRF combines the particle size (determined by laser diffraction) and the probability factor, integrated across the complete particle size distribution. It is important to recognise that the EN481 probability is based on aerodynamic size as opposed to the spherical equivalent diameter measured by laser diffraction techniques A size weighting is then applied based on the probability function given in EN481 and expressed as a SWeRF percentage of the bulk. The methodology employed for the calculation of SWeRF is derived from “SWeRF – A Method for Estimating the Relevant Fine Fraction in Bulk Materials for Classification and Labelling Purposes

Dose descriptor:

other: SWeRF Petrit T Lot 17100406

Effect level:

ca. 3.2 other: SWeRF Bulk Powder (%)

Remarks on result:

other: Calculation of SWeRF from a Particle Size Distribution

Remarks:

The probability of a particle reaching the alveoli region of the lung is a function of its aerodynamic size (Dae) and the probability specified in the EN481 standard1. The principle behind SWeRF combines the particle size (determined by laser diffraction) and the probability factor, integrated across the complete particle size distribution. It is important to recognise that the EN481 probability is based on aerodynamic size as opposed to the spherical equivalent diameter measured by laser diffraction techniques A size weighting is then applied based on the probability function given in EN481 and expressed as a SWeRF percentage of the bulk. The methodology employed for the calculation of SWeRF is derived from “SWeRF – A Method for Estimating the Relevant Fine Fraction in Bulk Materials for Classification and Labelling Purposes

Dose descriptor:

other: SWeRF Petrit T Lot 17100411

Effect level:

ca. 2.9 other: SWeRF Bulk Powder (%)

Remarks on result:

other: Calculation of SWeRF from a Particle Size Distribution

Remarks:

Calculation of SWeRF from a Particle Size Distribution

Mortality:

N/A

Clinical signs:

other: N/A

Body weight:

N/A

Gross pathology:

N/A

Please see attached for the Result Summary: This contains graphs that can't be added in IUCLID 

Interpretation of results:

GHS criteria not met

Conclusions:

In accordance with the CLP Regulation, industrial minerals producers have conducted a Review and Hazard Assessment of the health effects of respirable crystalline silica and have jointly determined it best and appropriate to classify crystalline silica (fine fraction) (quartz (fine fraction) and cristobalite (fine fraction)) as STOT RE 1 for the silicosis hazard. This is because particles of crystalline silica (fine fraction) may become airborne during handling and use in the workplace, creating respirable crystalline silica (RCS).
STOT refers to Specific Target Organ Toxicity. RE refers to “Repeated Exposure”. Based upon scientific evidence, it is generally necessary to inhale significant quantities of RCS in an occupational setting for prolonged and repeated periods of time before any possible long-term health effect may occur.
This classification applies to the fine fraction of quartz and cristobalite only, because it is scientifically demonstrated that it is only this fraction of crystalline silica, when made airborne, which may cause health effects. It is also in compliance with the CLP Regulation which allows consideration of the physical form(s) or physical state(s) of substance or mixture.
As a consequence of this classification, mixtures and substances containing crystalline silica (fine fraction), whether in the form of an identified impurity, additive or individual constituent, are classified as:
STOT RE 1, if the crystalline silica (fine fraction) concentration is equal to, or greater than 10%;
STOT RE 2, if the crystalline silica (fine fraction) concentration is between 1 and 10%.
If the crystalline silica (fine fraction) content in mixtures and substances is below 1%, no classification is required.

Therefore, no classification for this substance is required

Executive summary:

				Crystalline Silica* Content (bulk)		SWeRF
Ref	SampleDescription	R.I	Density (g/cm3)	Quartz(%)	Cristobalite(%)	Bulk Powder(%)	Cryst.Silica (%)
1	Petrit T Lot17100300	1.97	2.81	1.4	0.2	2.7	0.0
2	Petrit T Lot17100406	1.97	2.81	2.4	0.2	3.2	0.1
3	Petrit T Lot17100411	1.97	2.81	1.8	0.2	2.9	0.1

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5.07 mg/m³ air

Acute toxicity: via dermal route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: dermal

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The available identification data for the Target and the Source substance support the read-across hypothesis. Adequate, reliable and available scientific information indicate that the Target and Source substance have, or are very likely to have, similar (eco)toxicological properties. There are no indications that constituents other than those identified for the substances or impurities may influence the validity of the read-across. There is no evidence that additional toxicological mechanisms, other than those identified in the read-across hypothesis, may be acting or have an adverse effect on the validity of the read-across.

Reason / purpose for cross-reference:

read-across source

Limit test:

no

Preliminary study:

As it was known that there is no evidence of dermal toxicity, main test was made with maximum possible concentration of slags and crushed natural stone

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 4 000 mg/kg bw

Based on:

test mat.

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

BOS: rats OECD 402: LD50 > 4000 mg/kg Crushed natural stone: rats OECD 402: LD50 > 4000 mg/kg

Executive summary:

To test the dermal toxicity of slags, steelmaking, converter (BOS) and crushed stone from a quarry in the vicinity of Serra, Brasilia, tests were performed following OECD guideline 402 in Wistar rats. Fine-ground BOS and crushed stone were dosed, in their original form, at 4 g/kg bw (body weight) under semi-occlusive dressing for 24 h. After dosing, the patches were removed and the animals were observed for a post exposure period of 14 days. The LD₅₀ was > 4000 mg/kg bw for each test material.

Slags, steelmaking, converter (BOS) and natural stone from a quarry in Serra, Brasilia, are not toxic via the dermal route, and do not need to be classified as dermal toxicants. No signal word and no hazard statement is required.

Reference 2

Endpoint:

acute toxicity: dermal

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The available identification data for the Target and the Source substance support the read-across hypothesis. Adequate, reliable and available scientific information indicate that the Target and Source substance have, or are very likely to have, similar (eco)toxicological properties. There are no indications that constituents other than those identified for the substances or impurities may influence the validity of the read-across. There is no evidence that additional toxicological mechanisms, other than those identified in the read-across hypothesis, may be acting or have an adverse effect on the validity of the read-across.

Reason / purpose for cross-reference:

read-across source

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 4 000 mg/kg bw

Based on:

test mat.

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

SMS: rats OECD 402: LD50 > 4000 mg/kg Crushed natural stone: rats OECD 402: LD50 > 4000 mg/kg

Executive summary:

To test the dermal toxicity of slags, steelmaking (SMS), and crushed stone from a quarry in the vicinity of Serra, Brasilia, tests were performed following OECD guideline 402 in Wistar rats. Fine-ground SMS and crushed stone were dosed, in their original form, at 4 g/kg bw (body weight) under semi-occlusive dressing for 24 h. After dosing, the patches were removed and the animals were observed for a post exposure period of 14 days. The LD₅₀ was > 4000 mg/kg bw for each test material.

Slags, steelmaking (SMS), and natural stone from a quarry in Serra, Brasilia, are not toxic via the dermal route, and do not need to be classified as dermal toxicants. No signal word and no hazard statement is required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 000 mg/kg bw

Additional information

Inhalation

None of the animals died in a group of six rats exposed to mean achieved atmosphere concentration of 5.07 mg/L.  It was therefore considered that the acute inhalation median lethal concentration (4 hour LC50) of the test item in the Wistar strain rat was greater than 5.07 mg/L.

The test item does not meet the criteria for classification according to Regulation (EC) No. 1272/2008, relating to the Classification, Labelling and Packaging of Substances and Mixtures.

The test item does not meet the criteria for classification according to the Globally Harmonized System of Classification and Labelling of Chemicals.

Justification for classification or non-classification

In accordance with the CLP Regulation, No 1272/2008, classification is required for acute oral toxicity if the LD50 values are less than or equal to 2000 mg/kg bw. The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was considered to be greater than 2000 mg/kg body weight.  Therefore, the test material does not meet the criteria for classification.