Palladium dihydroxide

Additional toxicological data

Administrative data

Endpoint:

additional toxicological information

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Non-GLP, follows a standard operating procedure, available as an unpublished report, reliable without restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Standard Operating Procedure (SOP) prepared by Eurometaux on November 2010

Deviations:

no

Principles of method if other than guideline:

A bio-accessibility testing study has been designed to assay the metal release of Palladium compounds in perspiration synthetic media. Metals or metallic compounds are subjected to a media that mimic perspiration for 7 days at 30 °C and without agitation. Samples are taken at 24 hours and 168 hours of incubation, filtered and the bio-accessible metal quantified by ICP-MS.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Palladium dihydroxide

EC Number:

235-219-2

EC Name:

Palladium dihydroxide

Cas Number:

12135-22-7

Molecular formula:

H2O2Pd

IUPAC Name:

palladium(2+) dihydroxide

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Palladium dihydroxide
- Analytical purity: 65.3 % w/w
- Purity test date: 28/03/2012
- Lot/batch No.: MM10121
- Other: Particle size distribution and specific surface area (BET analysis) values were taken from: Fraunhofer IKTS report N° 4198_4208_4214_4216 of 12.11.2012.
- d50 = 0.673 µm (50th percentile of the particle size cumulative distribution as measured by volume)
- d90 = 12.117 µm (90th percentile of the particle size cumulative distribution as measured by volume)
- BET = 133 m2/g

Results and discussion

Any other information on results incl. tables

Table 1. Palladium dihydroxide 7 days bio-elution test in perspiration mimetic fluid: Palladium released from blanks and samples at pH 6.5 ( 2 g/L mass loading), were recorded before the sample was added and after 24 and 168 hours of incubation. The results are reported in µg/L and µg/g.

 

	Perspiration test parameters				Vessel 1	Vessel 2	Vessel 3	Palladium, µg/L			Palladium, µg/g
Blanks	Time, hr	Temp., °C	O2,mg/L	pH	R1	R2	R3	Mean, µg/L	St. Dev.	CV, %	Mean, µg/g	CV, %
	Before	30.0	7.6	6.48	“0.41”	“0.20”	0.16	-	-	-	-	-
	24	30.0	6.3	6.10	0.06	0.06	0.06	0.06	0.002	4	-	-
	168	30.0	2.9	6.77	BDL	BDL	BDL	-	-	-	-	-
Pd(OH)2	Time, hr	Temp., °C	O2,mg/L	pH	R1	R2	R3	Mean, µg/L	St. Dev.	CV, %	Mean, µg/g	CV, %
	Before	30.0	7.6	6.48	BDL	BDL	“0.37”	-	-	-	-	-
	24	30.0	6.3	6.87	11680.00	15616.00	13725.00	13673.67	1968.502	14	6825.46	14
	168	30.0	2.9	6.39	34474.00	33732.00	34054.00	34086.67	372.077	1	16992.36	1

CV: corresponds to the coefficient of variation between vessels (the ratio between the standard deviation and the mean of metal released).

Values between quotes are regarded as outliers and are not considered in the calculations (see outliers criteria in the Quality control section).

BDL: Below detection limit.

 

Table 2. Summary of metals solubility from Palladium dihydroxide sample; submitted to bio-elution tests in synthetic perspiration media. Metal release from the bio-elution tests is reported, as percentage of solubility, after 168 hours of incubation in perspiration fluid, respectively. SD = Standard Deviation, calculated from the 3 measurements performed to the 3 replica vessels.

 

Sample	% solubility in perspiration fluid
	168 h	SD
Palladium dihydroxide	2.6	0.03

Table 3. Results of the metal release per surface area exposed to the medium. The ratio between metal released in the bio-elution test, expressed in µg/g, and the specific surface area in m²/g are presented for Palladium dihydroxide.

Sample	Metal release in perspiration fluid [µg/m^2]
	168 h
Palladium dihydroxide	127.8

The control standards used to assure the quality of the measurements obtained with ICP-MS, demonstrated an adequate stability and accuracy of the instrument during the metal quantification of the bio-elution samples. All the QC samples showed metal concentration measurements in the range of 20% around the certified value of the standards; criterion used to assure the quality of the measurements.   

Applicant's summary and conclusion

Conclusions:

Palladium dihydroxide showed solubility of 2.6 % after 168 hours in perspiration fluid. After incubation in perspiration mimetic fluid, 13673.67 and 34086.67 µg/L (6825.46 and 16992.36 µg/g) of Palladium was released after 24 and 168 hours, respectively.

Executive summary:

A study to estimate metal bio-accessibility for Palladium dihydroxide in synthetic perspiration fluid, was performed following Standard Operating Procedure (SOP, Eurometaux, November 2010).

 

The test item was subjected to a media that mimics perspiration for 7 days at 30 °C and without agitation. Samples are taken at 24 hours and 168 hours of incubation, filtered and the bio-accessible metal quantified by ICP-MS.

 

Palladium dihydroxide showed solubility of 2.6 % after 168 hours in perspiration fluid. After incubation in perspiration mimetic fluid, 13673.67 and 34086.67 µg/L (6825.46 and 16992.36 µg/g) of Palladium was released after 24 and 168 hours, respectively.