Dirhodium trisulphate

Endpoint summary

Description of key information

In in vitro membrane barrier tests (CORROSITEX™ Assays), conducted according to OECD guidelines and to GLP, dirhodium trisulphate displayed mean breakthrough times of 20.04 and 11.69 minutes when tested as a solid (Lehmeier, 2013a) and in aqueous solution (Lehmeier, 2013b), respectively. The test substance is classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3-30 minutes (category 2) and 3-60 minutes (category 1) in the two assays respectively.
No relevant eye or respiratory tract irritation data were identified.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6-13 May 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD); to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: Not applicable.

Strain:

other: Not applicable.

Details on test animals or test system and environmental conditions:

The CORROSITEX™ Assay is a standardized, quantitative in vitro test for skin corrosivity and has been validated by the ECVAM for testing acids, bases and their derivatives.

The test was performed on a synthetic macromolecular bio-barrier membrane resting on top of a chemical detection system (CDS). The BIOBARRIER was prepared at least 2 hours prior to tests. BIOBARRIER diluent and matrix powder were combined and heated to 68 deg C under smooth agitation. After complete dissolution, the solution was allowed to sit for 5 minutes. 200 µl of the BIOBARRIER were pipetted into each membrane disc, set on the tray and kept in the cold (2-8 deg C) for at least 2 hours.

Type of coverage:

other: Not applicable.

Preparation of test site:

other: Not applicable.

Vehicle:

unchanged (no vehicle)

Controls:

other: Negative control: citric acid (10% aq.); positive controls: nitric acid (69%), phosphoric acid (85%)

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

Up to 1 hour.

Observation period:

The test system was observed until a reaction was detected (or for a total of 1 hour).

Number of animals:

Not applicable.

The test was performed on a total of eight BIOBARRIERS (four BIOBARRIERS for the test item).

Details on study design:

Test system:
The CORROSITEX™ test system was purchased from Invitro International, Irvine, CA 92614.

Qualification test:
This stage was carried out to ensure the sample is compatible with the CORROSITEX™ test system. 100 mg of the test substance was added to the Qualify test tube, shaken and left to stand for one minute. A colour change or change in consistency of the CDS indicates that the test material is qualified for the assay.

Categorisation test:
To establish the category cut-off times for the sample, 100 mg of the test substance was added to tubes labelled A and B. After shaking, a colour change observed in either tube was matched to the corresponding CORROSITEX™ colour charts. Test material with high acid/alkaline reserves are defined as category 1, and those with low acid/alkaline reserves as category 2. If no colour is observed, or if the test item is strongly coloured, a CONFIRM reagent is used followed by pH testing.

Classification test:
The test was performed in vials that came pre-filled with the CDS. Four replicate vials were used for the test substance. The CDS vials were warmed to room temperature (17-25 deg C) before use. A BIOBARRIER membrane disc was placed on top of a vial filled with CDS. 500 mg of the test item was placed on top of the BIOBARRIER membrane disc and starting time recorded. This was repeated with the remaining test vials, staggering each start time. The vials were observed for a colour-change reaction. The exact time to react was recorded for each vial.

Testing of positive and negative control substances:
Positive (nitric acid and phosphoric acid) and negative (citric acid) control substances were tested following the same procedure as the test substance assay. The expected reaction time ranges of the positive and negative control substances are within 3 minutes, 3 - 60 minutes and >60 minutes, respectively.

Data compilation:
The CORROSITEX™ time was calculated for each replicate by subtracting the start time from the detection time. The mean CORROSITEX™ time was calculated for the four test vials. Using the corrosivity assignment time table the appropriate Packing Group Classification was assigned.

Irritation / corrosion parameter:

other: CORROSITEX time (minutes)

Run / experiment:

mean of 4 replicates

Value:

20.04

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Qualification/categorisation test:

The test substance was compatible with the CORROSITEX™ test system. As the sample was intensely coloured, any colour-change reaction in the categorisation tubes was indistinct. Based on pH measurement the test substance was assigned to Category 2.

 

Positive and negative control test substances:

The reaction times of positive controls nitric acid and phosphoric acid were 1.97 and 16.42 minutes, respectively. The reaction time of the negative control was 67.67 minutes. The acceptance criteria for the control substances were therefore fulfilled.

 

CORROSITEX™ Assay:

The mean time of the test substance to activate the CDS was 20.04 minutes.

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Remarks:

Migrated information

Conclusions:

In an in vitro membrane barrier test (CORROSITEX™ Assay), conducted according to OECD guidelines and GLP, dirhodium(III) trisulphate (solid) displayed a mean breakthrough time of 20.04 minutes. The test substance is classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3-30 minutes (category 2).

Executive summary:

In a good quality GLP study, conducted according to OECD test guideline 435, the potential of dirhodium(III) trisulphate (solid) to induce skin corrosion was assessed in the "in vitro membrane barrier test (CORROSITEX™ Assay)".

The test item was placed on top of a BIOBARRIER membrane which was sat on a chemical detection system (CDS) in a vial. Corrosivity is determined on the ability (measured by the time taken) of a chemical to break through the barrier and subsequently activate the underlying CDS (as seen by a colour or consistency change). The mean time required for dirhodium(III) trisulphate (solid) to activate the CDS was 20.04 minutes (mean of 4 replicates).

The test substance is therefore classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3 -30 minutes (category 2).

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6-13 May 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD); to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: Not applicable.

Strain:

other: Not applicable.

Details on test animals or test system and environmental conditions:

The CORROSITEX™ Assay is a standardized, quantitative in vitro test for skin corrosivity and has been validated by the ECVAM for testing acids, bases and their derivatives.

The test was performed on a synthetic macromolecular bio-barrier membrane resting on top of a chemical detection system (CDS). The BIOBARRIER was prepared at least 2 hours prior to tests. BIOBARRIER diluent and matrix powder were combined and heated to 68 deg C under smooth agitation. After complete dissolution, the solution was allowed to sit for 5 minutes. 200 µl of the BIOBARRIER were pipetted into each membrane disc, set on the tray and kept in the cold (2-8 deg C) for at least 2 hours.

Type of coverage:

other: Not applicable.

Preparation of test site:

other: Not applicable.

Vehicle:

unchanged (no vehicle)

Controls:

other: Negative control: citric acid (10% aq.); positive controls: nitric acid (69%), phosphoric acid (85%)

Amount / concentration applied:

500 µL

Duration of treatment / exposure:

Up to 4 hours.

Observation period:

The test system was observed until a reaction was detected (or for a total of 4 hours).

Number of animals:

Not applicable.

The test was performed on a total of eight BIOBARRIERS (four BIOBARRIERS for the test item).

Details on study design:

Test system:
The CORROSITEX™ test system was purchased from Invitro International, Irvine, CA 92614.

Qualification test:
This stage was carried out to ensure the sample is compatible with the CORROSITEX™ test system. 150 µl of the test substance was added to the Qualify test tube, shaken and left to stand for one minute. A colour change or change in consistency of the CDS indicates that the test material is qualified for the assay.

Categorisation test:
To establish the category cut-off times for the sample, 150 µl of the test substance was added to tubes labelled A and B. After shaking, a colour change observed in either tube was matched to the corresponding CORROSITEX™ colour charts. Test material with high acid/alkaline reserves are defined as category 1, and those with low acid/alkaline reserves as category 2. If no colour is observed, or if the test item is strongly coloured, a CONFIRM reagent is used followed by pH testing.

Classification test:
The test was performed in vials that came pre-filled with the CDS. Four replicate vials were used for the test substance. The CDS vials were warmed to room temperature (17-25 deg C) before use. A BIOBARRIER membrane disc was placed on top of a vial filled with CDS. 500 µl of the test item was placed on top of the BIOBARRIER membrane disc and starting time recorded. This was repeated with the remaining test vials, staggering each start time. The vials were observed for a colour-change reaction. The exact time to react was recorded for each vial.

Testing of positive and negative control substances:
Positive (nitric acid and phosphoric acid) and negative (citric acid) control substances were tested following the same procedure as the test substance assay. The expected reaction time ranges of the positive and negative control substances are within 3 minutes, 3 - 60 minutes and >60 minutes, respectively.

Data compilation:
The CORROSITEX™ time was calculated for each replicate by subtracting the start time from the detection time. The mean CORROSITEX™ time was calculated for the four test vials. Using the corrosivity assignment time table the appropriate Packing Group Classification was assigned.

Irritation / corrosion parameter:

other: CORROSITEX time

Run / experiment:

mean of 4 replicates

Value:

11.69

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Qualification/categorisation test:

The test substance was compatible with the CORROSITEX™ test system. As the sample was intensely coloured, any colour-change reaction in the categorisation tubes was indistinct. Based on pH measurement the test substance was assigned to Category 1.

 

Positive and negative control test substances:

The reaction times of positive controls nitric acid and phosphoric acid were 1.97 and 16.42 minutes, respectively. The reaction time of the negative control was 67.67 minutes. The acceptance criteria for the control substances were therefore fulfilled.

 

CORROSITEX™ Assay:

The mean time of the test substance to activate the CDS was 11.69 minutes.

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Remarks:

Migrated information

Conclusions:

In an in vitro membrane barrier test (CORROSITEX™ Assay), conducted according to OECD guidelines and GLP, dirhodium(III) trisulphate (aqueous solution) displayed a mean breakthrough time of 11.69 minutes. The test substance is classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3-60 minutes (category 1).

Executive summary:

In a good quality GLP study, conducted according to OECD test guideline 435, the potential of dirhodium(III) trisulphate (aqueous solution) to induce skin corrosion was assessed in the "in vitro membrane barrier test (CORROSITEX™ Assay)".

The test item was placed on top of a BIOBARRIER membrane which was sat on a chemical detection system (CDS) in a vial. Corrosivity is determined on the ability (measured by the time taken) of a chemical to break through the barrier and subsequently activate the underlying CDS (as seen by a colour or consistency change). The mean time required for dirhodium(III) trisulphate (aqueous solution) to activate the CDS was 11.69 minutes (mean of 4 replicates).

The test substance is therefore classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3 -60 minutes (category 1).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No relevant irritation/corrosion human data were identified.

 

In a good quality GLP study, conducted according to OECD test guideline 435, the potential of dirhodium trisulphate (solid) to induce skin corrosion was assessed in the "in vitro membrane barrier test (CORROSITEX™ Assay)". The test item was placed on top of a BIOBARRIER membrane which was sat on a chemical detection system (CDS) in a vial. Corrosivity is determined on the ability (measured by the time taken) of a chemical to break through the barrier and subsequently activate the underlying CDS (as seen by a colour or consistency change). The mean time required for dirhodium trisulphate (solid) to activate the CDS was 20.04 minutes (mean of 4 replicates). The test substance is therefore classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3 -30 minutes (category 2) (Lehmeier, 2013a).

 

In another good quality GLP study, conducted according to OECD test guideline 435, the potential of dirhodium trisulphate (in aqueous solution) to induce skin corrosion was assessed in the "in vitro membrane barrier test (CORROSITEX™ Assay)". The test item was placed on top of a BIOBARRIER membrane which was sat on a chemical detection system (CDS) in a vial. Corrosivity is determined on the ability (measured by the time taken) of a chemical to break through the barrier and subsequently activate the underlying CDS (as seen by a colour or consistency change). The mean time required for dirhodium trisulphate (in aqueous solution) to activate the CDS was 11.69 minutes (mean of 4 replicates). The test substance is therefore classified as "corrosive" sub category 1B, according to UN GHS criteria, as the mean time to activate the CDS was between 3 -60 minutes (category 1) (Lehmeier, 2013b).

 

No eye or respiratory tract data were identified.

Justification for selection of skin irritation / corrosion endpoint:
OECD guideline study, to GLP. Both these in vitro assays indicate a corrosive response and an identical classification (category 1B).

Effects on skin irritation/corrosion: corrosive

Justification for classification or non-classification

Based on the results of the available and reliable in vitro skin corrosion studies, dirhodium trisulphate should be classified as corrosive to the skin (category 1B) according to EU CLP criteria (EC 1272/2008). Substances that are corrosive to the skin are considered as leading to serious damage to the eyes. Consequently, dirhodium trisulphate should be classified for eye effects in Category 1 according to EU CLP criteria (EC 1272/2008).