Hematite, chromium green black

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is highly insoluble in water, hence indicating that aquatic toxicity is unlikely to occur

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-09-07 to 2010-04-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

deviations from the guideline, which do not effect the validity of the study: (a) the 28-day test with a loading of 1 mg/L was conducted at pH 6 instead of 5.5 (b) `mass balance (%) after completion of the transformation test´ is missing.

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

Deviations:

yes

Remarks:

please refer to the field "Rationale for reliability incl. deficiencies" above

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2009-06-19

Type of method:

flask method

Remarks:

transformation/dissolution

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Cr, Al

Loading of aqueous phase:

0.1 g/L

Incubation duration:

24 h

Test conditions:

pH: >= 6.08 <= 6.1
Temp: 22.5 °C

Remarks on result:

other: < LOD

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Cr, Al

Loading of aqueous phase:

0.1 g/L

Incubation duration:

24 h

Test conditions:

pH: >= 8.04 <= 8.08
Temp.: 22.5 °C

Remarks on result:

other: < LOD

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Cr

Loading of aqueous phase:

0.1 g/L

Incubation duration:

7 d

Test conditions:

pH: >= 6.07 <= 6.11
Temp.: 22.5 °C

Remarks on result:

other: < LOD

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

2.4 µg/L

Element analysed:

Al

Loading of aqueous phase:

0.1 g/L

Incubation duration:

7 d

Test conditions:

pH: >= 6.07 <= 6.11
Temp.: 22.5 °C

Remarks on result:

other: SD: +/- 0.4 µg/L

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.05 µg/L

Element analysed:

Cr, Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH: >=6.05<=6.12, Temp.: 22.5 °C

Remarks on result:

other: < LOD

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Cr, Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH >= 6.07 <= 6.08, Temp.: 22.5 °C

Remarks on result:

other: < LOD

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Cr, Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH: >= 6.04 <= 6.06
Temp.: 22.5 °C

Remarks on result:

other: < LOD

Details on results:

The analytical method was shown to be suitable for low content determination of chromium and aluminium in aqueous samples due to the technique ICP-MS.
The analysed range from 0.1 to 10.0 µg/L was found to be linear for Cr and Al (correlation coefficient > 0.99 for either metal).
The instrumental limit of detection (I.D.L.) defined as the lowest calibration level, was 0.1 µg/L for Cr and Al, respectively.
The limit of quantification (L.O.Q.) of the method was 1 µg/L for Cr and Al, defined as the lowest fortification level.
The limit of detection (L.O.D.) of the method, defined as 50% of the lowest fortification level, was 0.5 µg/L for either metal.
Concentrations higher than the limit of detection but less than the limit of quantification were designated as <1 µg/L for Cr and Al.
The analytical method was shown to be suitable for low content determination of chromium and aluminium in aqueous samples due to the technique ICP-MS.
The test was performed by spiking each of the test media (using three replicates) with known amounts of Cr and Al at two fortification levels (1 µg/L for the low level and 10 µg/L for the high level) using the SS 2 and SS 1 solution of 1 mg/L and 10 mg/L, respectively.
For precision, the SANCO/3029/99 rev. 4 guideline requires a RSD % lower than 20 % for each fortification level; therefore the precision of the analytical method at low and high fortification levels can be considered acceptable.
The precision of the analytical method has been fixed at 10 % taking into account the results obtained.
For accuracy, the SANCO/3029/99 rev. 4 guideline requires individual recovery values in the range from 70 to 110 % with mean value between 80 to 100 % at each fortification level, therefore the accuracy of the analytical method can be considered acceptable.
Considering the low concentrations tested (low fortification level 1 µg/L and high fortification level 10 µg/L), the precision of the analytical method fixed at 10 % and the complexity of the aqueous matrices tested the accuracy of the analytical method can be considered acceptable.
From the data and results of the accuracy test it can be concluded that no matrix effect was observed and no contribution of the filter procedure was observed.

Screening Test at 0.1 g/L		^52Cr (µg/L)	^27Al (µg/L)
pH 6 T 24 h	Mean	n.d.	n.d.
	S.D.	-	-
	RSD %	-	-
pH 8 T 24 h	Mean	n.d.	n.d.
	S.D.	-	-
	RSD %	-	-

Conclusion of the screening test:

Dissolved Al or Cr concentrations were below the LOD at both pH levels. Therefore, pH 6 was selected for the full test assuming that the dissolution of metal oxides (i.e. this pigment) is maximized at the lower pH (in acidic medium).

Full Test 7 days at 0.1 g/L pH 6		^52Cr (µg/L)	^27Al (µg/L)
T 1 day	Mean	n.d.	3.9
	S.D.	-	0.04
	RSD %	-	1.0 %
T 4 days	Mean	n.d.	3.739
	S.D.	-	0.113
	RSD %	-	3.02 %
T 7 days	Mean	n.d.	2.414
	S.D.	-	0.389
	RSD %	-	16.13 %

Full Test 28 days at 1 mg/L pH6		^52Cr (µg/L)	^27Al (µg/L)
T1 day	Mean	n.d.	n.d.
	S.D.	-	-
	RSD %	-	-
T7 days	Mean	n.d.	n.d.
	S.D.	-	-
	RSD %	-	-
T14 days	Mean	n.d.	n.d.
	S.D.	-	-
	RSD %	-	-
T28 days	Mean	n.d.	n.d.
	S.D.	-	-
	RSD %	-	-

Test conditions:

- The pH was inside of the acceptable range (pH6 +0.2 units) in a range of 6.02 to 6.10

- The temperature was inside of the acceptable range (20 -25 +/- 2) in a range of 22.4 to 22.6

- The O2 -concentration was always above the accaptable limit of 70 % in a range of 79.7 % to 81.7 %

- The within-vessel values and the between-vessel values could not be determined, because the concentrations of Cr and Al were below the LOD (0.5 µg/L for Al and Cr)

Conclusions:

The transformation/dissolution of test item hematite chromium green black is in most cases below the L.O.D. (< 0.5 µg/L) at pH 6.

- after 7 days, 1 mg/L: < 0.5 µg Cr/L, <0.5 µg Al/L
- after 28 days, 1 mg/L: < 0.5 µg Cr/L, < 0.5 µg Al/L
- after 7 days, 100 mg/L: < 0.5 µg Cr/L, 2.4 µg Al/L

Thus, this pigment is considered environmentally inert.