Activated Carbon - Low Density Skeleton

Endpoint summary

Description of key information

- Acute oral toxicity:
Acute toxic class method (OECD 423): LD50 > 2000 mg/kg bw (female rat)
- Acute inhalation toxicity (read-across from steam-activated carbon):
Standard acute method: LC50 > 8.5 mg/L

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:

02 March 2010 - 25 March 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

performed under GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class 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

Remarks:

Statement of Compliance

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: RccHan: WIST(SPF)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories B.V., Kreuzelweg 53, 5961 NM Horst / The Netherlands
- Age at study initiation: 10 weeks
- Weight at study initiation: 169.1 g – 178.7 g
- Fasting period before study: approximately 18 to 19 hours
- Housing: In groups of three in Makrolon type-4 cages with wire mesh tops and standard softwood bedding
- Diet: Pelleted standard Provimi Kliba 3433 rat/mouse maintenance diet
- Water: Community tap water from Füllinsdorf ad libitum
- Acclimation period: 02 March 2010 to 08 March 2010 (Group 1); 02-March 2010 to 10 March 2010 (Group 2)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 30-70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 02 March 2010 To: 23/25 March 2010

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

purified

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 0.2 g/mL
- Justification for choice of vehicle: The vehicle was chosen after a non-GLP solubility trial which was performed before the study initiation date. The test item was prepared at 20 % in purified water (w/w), which resulted in a black dispersion that was considered orally applicable.

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg body weight

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: not specified

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

2 groups of 3 female animals

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded within the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15.
- Necropsy of survivors performed: yes, on day 15
- Other examinations performed: clinical signs, body weight, mortality, viability, macroscopic findings.

Statistics:

No statistical analysis was performed.

Preliminary study:

Not relevant

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Remarks on result:

other: No treatment related effects were observed.

Mortality:

No mortality occurred.

Clinical signs:

other: Clinical signs of slight to moderate degree were observed in the animals of group 1, including sedation, hunched posture and ruffled fur and laborated breathing. All symptoms were completely reversed by test day 2 or 3. No clinical signs were observed in

Gross pathology:

No macroscopic findings were recorded at necropsy.

Interpretation of results:

other: not classified

Remarks:

based on CLP criteria

Conclusions:

No treatment related effects were found under the conditions of this study. The median lethal dose of Chemically Activated Carbon after single oral administration to female rats, observed over a period of 14 days, is: LD50 (female rat): greater than 2000 mg/kg body weight. The substance does not have to be classified according to the EU classification criteria outlined in 1272/2008/EC.

Executive summary:

The acute oral toxicity of Chemically Activated Carbon in the rat was assessed by using the acute toxic class method. The study was carried out based on OECD guideline 423. Two groups, each consisting of three female RccHan:WIST (SPF) rats, were treated with Chemically Activated Carbon by single oral gavage administration at a dosage of 2000 mg/kg body weight. The test item was formulated in purified water at a concentration of 0.2 g/mL and administered at a dosing volume of 10 mL/kg.

No intercurrent deaths occurred during the course of the study.

Clinical signs of slight to moderate degree were observed in the animals of group 1, including sedation, hunched posture and ruffled fur and laborated breathing. All symptoms were completely reversed by test day 2 or 3. No clinical signs were observed in the animals of group 2. For all animals, black feces were noted on test day 2 or 3, which was most likely a consequence of the black test item.

The body weight of the animals was within the range commonly recorded for this strain and age.

No macroscopic findings were recorded at necropsy.

The median lethal dose of Chemically Activated Carbon after single oral administration to female rats, observed over a period of 14 days, is: LD50 (female rat): greater than 2000 mg/kg body weight. The substance does not have to be classified according to the EU classification criteria outlined in 1272/2008.

Endpoint conclusion

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:

14 May 1980 - 28 May 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

Study seems to be conducted according to a method that equals OECD guideline 403, which was not yet adopted at that time. It is unclear if GLP conditions are maintained during study. Report is concise but clear. Due to the limitations of the study and its read-across purpose ( in accordance with the ECHA Practical guide #6 on the reporting of read-across in IUCLID), the study was assigned a Klimisch 2 rating.

Justification for type of information:

The justification for read across is attached as a separate document to the "Toxicological information" summary

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Remarks:

(guideline was not yet adopted in 1980)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington, Massachusetts
- Weight at study initiation:
Male: 251-285 g
Female: 227-239 g
- Housing: During exposure in a 100 liter plexiglass exposure chamber

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Bubbler
- Exposure chamber volume: 100 liter
- Source and rate of air:
Source 1: 10 L/min through calibrated flow meter into bubbler
Source 2: 14 L/min into bubbler (1 sec/13 seconds)
Air was diluted with 10 L/min before directed into exposure chamber
- System of generating particulates/aerosols: Three-neck bubbler

TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetry
- Samples taken from breathing zone: no, only directly from the center sampling port

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: No data
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): No data

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

1 h

Concentrations:

Nominal exposure concentration: 64.4 mg/L
Mean airborne test material concentration (gravimetry): 8.5 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Observations: before exposure, every 15 minutes during exposure, hourly for 4 hours after exposure and daily thereafter
Body weights: on day 0, 1, 2, 4, 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: gross necropsy

Statistics:

Not relevant

Preliminary study:

Not relevant

Sex:

not specified

Dose descriptor:

LC100

Effect level:

235 mg/L air (nominal)

Exp. duration:

1 h

Remarks on result:

other: All animals died (initial test)

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

64.4 mg/L air (nominal)

Exp. duration:

1 h

Remarks on result:

other: No deaths, but multiple effects were observed (contamination of fur, general stress, lung rales, weight loss, lung discoloration)

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

8.5 mg/L air (analytical)

Exp. duration:

1 h

Remarks on result:

other: No deaths, but multiple effects were observed (contamination of fur, general stress, lung rales, weight loss, lung discoloration)

Mortality:

No mortality was observed.

Clinical signs:

other: Animals visible exhibited labored breathing and intermittent gasping. Upon removal from the chamber mucoid nasal discharge, salivation, rapid or labored breathing, gasping, dry or moist rales, reduced activity, and wet or matted ano-genital fur were obser

Body weight:

Weight losses were seen in nearly all rats following exposure. Body weights recovered to pre-exposure values in males by day 4 and in females usually by day 7. Body weight in the second week were within the limits of normal expectation.

Gross pathology:

At necropsy, 5 male and 4 female rats showed treatment related foci or areas of lung discoloration (higher incidence than normally encountered)

Other findings:

Not relevant

Interpretation of results:

other: not classified

Remarks:

based on CLP criteria

Conclusions:

A one-hour inhalation exposure of rats to a dust of BPL 12 x 30 at a nominal concentration of 64.4 mg/L and mean airborne concentration of 8.5 mg/L did not produce mortality. However, irritation of the respiratory mucous membranes related to test material exposure was observed and residual lung discoloration was seen at necropsy. The LC50 was established to be >8.5 mg/L.

Executive summary:

This acute inhalation toxicity study in rats was conducted according to a method resembling OECD guideline 403. Male and female rats were exposed for one hour to BPL 12 x 30 at a nominal concentration of 64.4 mg/L and a mean airborne concentration of 8.5 mg/L. Rats were observed for 14 days after exposure.

Several effects were observed. All rats appeared heavily contaminated with the test material during and 14 days after the exposure period. Animals visible exhibited labored breathing and intermittent gasping. Upon removal from the chamber mucoid nasal discharge, salivation, rapid or labored breathing, gasping, dry or moist rales, reduced activity, and wet or matted ano-genital fur were observed. Recovery was apparent within 1 day. Slight dry rales was observed in most rats during the 14-day observation period. Weight losses were seen in nearly all rats following exposure. Body weights recovered to pre-exposure values in males by day 4 and in females usually by day 7. Body weights in the second week were within the limits of normal expectation. At necropsy, 5 male and 4 female rats showed foci or areas of lung discoloration.

As no deaths occured the tested concentration can be considered as LC0 (LC50 >8.5 mg/L). Following these results, the test substance does not need to be classified for acute inhalation toxicity according to the criteria outlined in Annex I of 1272/2008/EC .

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

The justification for read across is attached

Reason / purpose for cross-reference:

read-across source

Duration of exposure:

h

Preliminary study:

Not relevant

Sex:

not specified

Dose descriptor:

LC100

Effect level:

235 mg/L air (nominal)

Exp. duration:

1 h

Remarks on result:

other: All animals died (initial test)

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

64.4 mg/L air (nominal)

Exp. duration:

1 h

Remarks on result:

other: No deaths, but multiple effects were observed (contamination of fur, general stress, lung rales, weight loss, lung discoloration)

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

8.5 mg/L air (analytical)

Exp. duration:

1 h

Remarks on result:

other: No deaths, but multiple effects were observed (contamination of fur, general stress, lung rales, weight loss, lung discoloration)

Mortality:

No mortality was observed.

Clinical signs:

other: Animals visible exhibited labored breathing and intermittent gasping. Upon removal from the chamber mucoid nasal discharge, salivation, rapid or labored breathing, gasping, dry or moist rales, reduced activity, and wet or matted ano-genital fur were obser

Body weight:

Weight losses were seen in nearly all rats following exposure. Body weights recovered to pre-exposure values in males by day 4 and in females usually by day 7. Body weight in the second week were within the limits of normal expectation.

Gross pathology:

At necropsy, 5 male and 4 female rats showed treatment related foci or areas of lung discoloration (higher incidence than normally encountered)

Other findings:

Not relevant

Interpretation of results:

other: not classified

Remarks:

based on CLP criteria

Conclusions:

A one-hour inhalation exposure study was performed on AC-HDS, and the results are used for Read across to AC-LDS. Rats were exposed for one hour to a dust of BPL 12 x 30 at a nominal concentration of 64.4 mg/L and mean airborne concentration of 8.5 mg/L, exposure did not produce mortality. However, irritation of the respiratory mucous membranes related to test material exposure was observed and residual lung discoloration was seen at necropsy. The LC50 was established to be >8.5 mg/L.

Executive summary:

A one-hour inhalation exposure study was performed on AC-HDS, and the results are used for Read across to AC-LDS. This acute inhalation toxicity study in rats was conducted according to a method resembling OECD guideline 403. Male and female rats were exposed for one hour to BPL 12 x 30 at a nominal concentration of 64.4 mg/L and a mean airborne concentration of 8.5 mg/L. Rats were observed for 14 days after exposure.

Several effects were observed. All rats appeared heavily contaminated with the test material during and 14 days after the exposure period. Animals visible exhibited labored breathing and intermittent gasping. Upon removal from the chamber mucoid nasal discharge, salivation, rapid or labored breathing, gasping, dry or moist rales, reduced activity, and wet or matted ano-genital fur were observed. Recovery was apparent within 1 day. Slight dry rales was observed in most rats during the 14-day observation period. Weight losses were seen in nearly all rats following exposure. Body weights recovered to pre-exposure values in males by day 4 and in females usually by day 7. Body weights in the second week were within the limits of normal expectation. At necropsy, 5 male and 4 female rats showed foci or areas of lung discoloration.

As no deaths occured the tested concentration can be considered as LC0 (LC50 >8.5 mg/L). Following these results, the test and thus target substance does not need to be classified for acute inhalation toxicity according to the criteria outlined in Annex I of 1272/2008/EC .

Endpoint conclusion

Dose descriptor:

LC50

Value:

8 500 mg/m³ air

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because inhalation of the substance is likely

Additional information

No mortality or toxicity effects were observed in the key study for acute oral toxicity up to the highest dosage of 2000 mg/kg bw. Also no deaths were reported in the key study for acute inhalation toxicity (read-across from Activated Carbon - High Density Skeleton) at a tested concentration of 8.5 mg/L. However, body weight loss, respiratory mucous membrane irritancy and - at necropsy - lung discoloration were observed. The LD50 and LC50 were determined to be >2000 mg/kg bw and >8.5 mg/L for the oral and inhalation route, respectively.

Justification for classification or non-classification

Based on the results of the key studies, Activated Carbon - Low Density Carbon does not need to be classified for acute toxicity when considering the criteria outlined in Annex I of 1272/20008/EC .