Dicarbonyl(pentane-2,4-dionato-O,O')rhodium

Endpoint summary

Description of key information

The acute oral LD50 of rhodium dicarbonyl acetylacetonate was determined to be in the range of 50-500 mg/kg bw (Middleton and Husband, 1978). 
In a limit test, the acute dermal LD50 of acetylacetonatodicarbonyl rhodium (I) was found to exceed 2000 mg/kg bw (Collier, 1981).
No relevant acute inhalation toxicity data were identified.

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:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study does not follow modern guideline, but data are reasonaly well documented and scientifically acceptable. Limited reporting of test material (e.g. purity).

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Principles of method if other than guideline:

A range finding study using groups of two rats (one male, one female) at five dose levels was conducted to identify the highest dose at which no deaths occurred. In the main study, a further group of 10 rats (5 male, 5 female) was treated at this dose.

GLP compliance:

not specified

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: Olac, Shaws Farm, Blackthorn, Bicester, Oxon
- Age at study initiation: “young adult”
- Weight at study initiation: 170-235 g
- Fasting period before study: overnight
- Housing: 5 rats (of one sex) in polypropylene cages
- Diet (e.g. ad libitum):ad libitum oxoid maintenance diet supplied by Herbert C. Styles (Bewdley) Ltd
- Water (e.g. ad libitum): ad libitum
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): “thermostatically controlled room”
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): “controlled lighting conditions”

IN-LIFE DATES: From: To: no data

Route of administration:

oral: gavage

Vehicle:

vegetable oil

Details on oral exposure:

A single dose was administed orally by stomach tube using a rubber catheter. Test material was delivered in a total volume of 10 ml vegetable oil.

Doses:

Range finding study: 25, 50, 200, 500 and 2000 mg/kg bw.
Main study: 50 mg/kg bw.

No. of animals per sex per dose:

Range finding study: one rat/sex/dose
Main study: five rats/sex/dose

Control animals:

no

Details on study design:

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- Duration of observation period following administration: 14 days- Frequency of observations and weighing: Animals were weighed immediately prior to dosing. The animals were examined immediately after dosing, four-hours after dosing, and then daily for 14 days for signs of toxicity.
- Necropsy of survivors performed: no
- Other examinations performed: none

Statistics:

No statistical analysis was performed.

Sex:

male/female

Dose descriptor:

approximate LD50

Effect level:

> 50 - < 500 mg/kg bw

Mortality:

In the range-finding study, both the male and the female rats died (24 hrs and 4 days after dosing, respectively) at 2000 mg/kg bw. The females in the 500 and 200 mg/kg bw dose level groups died (at 4 days and 3 days after dosing, respectively). No deaths were seen at the 50 mg/kg bw dose level or below. In the main study, one of the group of five females died at the selected treatment level of 50 mg/kg bw. The remaining females and all five treated males survived the 14 day observation period.

Clinical signs:

other: Not reported.]

Gross pathology:

Not reported.]

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The acute oral LD50 value of rhodium dicarbonyl acetylacetonate in rats was established to be within the range of 50-500 mg/kg bw.

Executive summary:

The acute oral toxicity of rhodium dicarbonyl acetylacetonate was assessed in rats, using a method equivalent to OECD Test Guideline 401. In a range finding study, groups of Sprague-Dawley rats (1/sex/group) were administered the test item at doses of 25, 50, 200, 500 or 2000 mg/kg bw by stomach tube. Both rats died in the 500 and 2000 mg/kg bw dose groups, within four days of treatment. The female rat treated at 200 mg/kg bw died three days post-treatment. Therefore, in the main study, groups of five rats/sex were administered a dose of 50 mg/kg bw. One female rat died three days after treatment. The remaining animals survived the 14 day observation period and were reported to show “no overt signs of toxicity”. 

 

The acute oral median lethal dose (LD50) of rhodium dicarbonyl acetylacetonate was determined to be between 50 and 500 mg/kg bw. Based on the results of this study, rhodium dicarbonyl acetylacetonate should be classified for acute oral toxicity (category 3) according to EU CLP criteria (EC 1272/2008).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

50 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 January 1981 – 10 February 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study apparently performed according to the method described by Noakes DN and Sanderson DM (1969) Br. J. ind. Med. Vol. 26, P. 59-64, which has some deviations from current OECD guidelines. Limited reporting, notably of test material (e.g. purity).

Qualifier:

according to guideline

Guideline:

other: Noakes DN and Sanderson DM (1969) Br. J. ind. Med. Vol. 26, P. 59-64

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

The animals were prepared by closely clipping the hair “on the day of the test” (guideline states that this should be done approx. 24 hrs before the test), the animals weighed between 210 and 400 g (guideline suggests rats weighing 200-300 g be used) and

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Tuck and Sons Ltd, Battlesbridge, Essex
- Weight at study initiation: 210-400 g
- Housing: individually during the exposure period and then in groups of up to 5 in solid floor polypropylene cages furnished with softwood sawdust
- Diet: ad libitum rat diet supplied by Nottingham University, Sutton Bonington, Near Loughborough, Leicestershire
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Air changes (per hr): a minimum of 20 air changes/hr
- Photoperiod (hrs dark / hrs light): lighting cycle of 12 hrs on and 12 hrs off with no daylight

Type of coverage:

occlusive

Vehicle:

arachis oil

Details on dermal exposure:

TEST SITE
- Area of exposure: approx. 6 x 12 cm
- Type of wrap if used: elastic adhesive bandage backed with aluminium foil

REMOVAL OF TEST SUBSTANCE
- Washing (if done): skin and surrounding hair sponged thoroughly with detergent and warm water, rinsed and dried.
- Time after start of exposure: 24 hrs

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 g/kg bw
- Concentration (if solution): 200 mg/ml
- Constant volume or concentration used: yes
- For solids, paste formed: yes - suspension

VEHICLE
- Amount(s) applied (volume or weight with unit): 10 ml/kg bw

Duration of exposure:

24 hrs

Doses:

2 g/kg bw

No. of animals per sex per dose:

5 rats/sex

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: ½, 1 and 4 hrs following treatment, and then once daily for 14 days
- Necropsy of survivors performed: yes, one male and one female
- Other examinations performed: clinical signs

Statistics:

Acute dermal median lethal dose (LD50)

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Remarks on result:

other: No deaths reported.

Mortality:

There were no mortalities throughout the 14 day observation period.

Clinical signs:

other: All animals showed subdued activity at the ½ hr observation period. No such effects were seen after 1 hr and no other clinical effects were noted.

Gross pathology:

No abnormal macroscopic lesions were seen in one male and one female survivor at termination of the study. (OECD guidelines recommend all animals are necropsied.)

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In a limit test, the acute percutaneous median lethal dose (LD50) of acetylacetonatodicarbonyl rhodium (I) in the rat was found to be >2000 mg/kg bw.

Executive summary:

Acetylacetonatodicarbonyl rhodium (I) was tested for its acute dermal toxicity in rats, using a method analogous to OECD Test Guideline 402 (with some minor deviations). A group of 5 male and 5 female Sprague-Dawley rats were treated dermally (application to clipped skin under occlusion; skin was clipped on the day of the test whereas the guideline recommends that this should be done approximately 24-hr before the test) with the test item at 2 g/kg bw (in arachis oil). After 24 hours the patch was removed, the skin washed and rinsed, and the rats observed for 14 days. No deaths or signs of overt toxicity were seen in either sex and there were no abnormal macroscopic lesions in the single necropsied male and female (OECD guidelines recommend all animals are necropsied).

 

Based on the results of this study, acetylacetonatodicarbonyl rhodium (I) should not be classified for acute dermal toxicity according to EU CLP criteria (EU 1272/2008).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

No relevant human acute toxicity data were identified.

The acute oral toxicity of rhodium dicarbonyl acetylacetonate was assessed in rats, using a method equivalent to OECD Test Guideline 401. In a range finding study, groups of Sprague-Dawley rats (1/sex/group) were administered the test item at doses of 25, 50, 200, 500 or 2000 mg/kg bw by stomach tube. Both rats died in the 500 and 2000 mg/kg bw dose groups, within four days of treatment. The female rat treated at 200 mg/kg bw died three days post-treatment. Therefore, in the main study, groups of five rats/sex were administered a dose of 50 mg/kg bw. One female rat died three days after treatment. The remaining animals survived the 14 day observation period and were reported to show “no overt signs of toxicity”. The acute oral median lethal dose (LD50) of rhodium dicarbonyl acetylacetonate was determined to be between 50 and 500 mg/kg bw (Middleton & Husband, 1978).

 

Acetylacetonatodicarbonyl rhodium (I) was tested for its acute dermal toxicity in rats, using a method analogous to OECD Test Guideline 402 (with some minor deviations). A group of 5 male and 5 female Sprague-Dawley rats were treated dermally (application to clipped skin under occlusion; skin was clipped on the day of the test whereas the guideline recommends that this should be done approximately 24-hr before the test) with the test item at 2 g/kg bw (in arachis oil). After 24 hours the patch was removed, the skin washed and rinsed, and the rats observed for 14 days. No deaths or signs of overt toxicity were seen in either sex and there were no abnormal macroscopic lesions in the single necropsied male and female (OECD guidelines recommend all animals are necropsied) (Collier, 1981).

No acute inhalation toxicity data were identified, or are required at this tonnage (1-10 tpa).

Justification for selection of acute toxicity – oral endpoint
OECD guideline equivalent study, and the only acute oral toxicity study available.

Justification for selection of acute toxicity – dermal endpoint
OECD guideline equivalent study (with some minor deviations), and the only acute dermal toxicity study available.

Justification for classification or non-classification

Based on the results of the available and reliable acute oral rat study, dicarbonyl(pentane-2,4-dionato-O,O')rhodium should be classified for acute oral toxicity (category 3) according to EU CLP criteria (EC 1272/2008).

 

No classification for acute dermal toxicity is required, based on the results of the available and reliable acute dermal rat study with dicarbonyl(pentane-2,4-dionato-O,O')rhodium.

No evidence of specific target organ toxicity was noted. As such, classification for STOT-SE is not considered appropriate.