Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no hazard identified

Marine water

Hazard assessment conclusion:
no hazard identified

STP

Hazard assessment conclusion:
no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:
insufficient hazard data available (further information necessary)

Sediment (marine water)

Hazard assessment conclusion:
insufficient hazard data available (further information necessary)

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
insufficient hazard data available (further information necessary)

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
insufficient hazard data available (further information necessary)

Additional information

Conclusion on classification

It is important to point out that the substances being registered in this dossier are sparingly soluble forms of aluminium and not soluble metal salts. Information is provided below on the classification of the soluble form – aluminum chloride and on an evaluation of the transformation-dissolution of aluminum powders. An overall conclusion on classification is drawn and presented.

7.6.1 Soluble Aluminium Salts and Implications for Sparingly Soluble Aluminium Substances

Data waiving

 

Reason:Soluble aluminium salts are not classified; therefore less soluble forms of aluminium are less hazardous and also not classified.

Justification:Available data indicate that aluminium salts are relatively non toxic and this was sufficient for the EU Classification and Labelling Committee to determine that there was no need for classification of aluminium chloride. Therefore it is also concluded that aluminium massive and sparingly soluble forms of aluminium are highly insoluble and non-hazardous. The sections above have provided data on a BLM model that can be used to assess potential for toxicity in the pH range of 5-6. Work is continuing on this model. 

7.6.2 Classification of Sparingly Soluble Forms of Aluminium

 

Conclusions

 

Al203– Aluminium Oxide:                                no acute or chronic classification

Al(OH)3- Aluminium Hydroxide:                                 no acute or chronic classification

Aluminium Powders           :Large Powders:                no acute or chronic classification

: Small Powders (6 mµ):   no acute or chronic classification

Aluminium Massive:                                                        no acute or chronic classification

 

Lines of Evidence for No Classification

 

  1. Al Chloride (soluble salt) was not classified by the C&L Committee in 1999 and therefore less soluble forms of Al would also logically not classify.
  2. Transformation/dissolution (T/D) tests followed testing of the T/D solutions with fish, daphnids, and algae. These tests indicated that the above forms of Al do not classify.
  3. T/D tests performed at CIMM indicated insufficient solubility of the above forms of Al to classify.

These lines of evidence are examined in the sections below.

 

 

 

 

Review of the Existing Transformation – Dissolution and Toxicity Data on Al

 

The following review was undertaken to provide an updated assessment of the data available to date for determining the classification outcome of sparingly soluble metal powders and massive aluminium. 

 

Available data indicate that aluminium salts are relatively non toxic and this was sufficient for the EU Classification and Labelling Committee (1999) to determine that there was no need for classification of aluminium chloride. Therefore it was also concluded that aluminium massive and sparingly soluble forms of aluminium are highly insoluble and non-hazardous.The rules indicate that if the soluble metal does not classify, then sparingly soluble metal compounds also do not classify. The EU Classification and Labelling Committee has officially stated AlCl3does not classify for aquatic species. In principal, additional testing for classification is not needed. However, the aluminium industry decided to evaluate the dissolution of Al substances as a means of demonstrating proper stewardship of its products. 

 

Studies reported in the literature have been performed repeatedly with test solutions based on soluble salts with aluminium concentrations above that of its solubility limit. Due to physical effects of precipitated material most of these studies are meaningless for the investigation of intrinsic toxicity. Aluminium ions released to surface waters quickly form insoluble aluminium hydroxides in mixing zones. These colloids can sorb to fish gills resulting in asphyxiation and mortality in rare instances. In laboratory studies, reports of asphyxiation are common and true or intrinsic toxicity appears to be lacking. The rapid formation of the complex hydroxides in neutral and alkaline waters complicates the assessment for classification for several reasons. First, the observed mortality is does not appear to be due to intrinsic toxicity. Second, the LC and EC50 values are typically above 1 mg/L (there are a couple of values in the 0.5-1.0 mg/L range) and all of the effects values are above the solubility limit of aluminium hydroxide. A report on the solubility of Al in OECD test media is attached and was summarised at the January 26, 2010 meeting with ECHA (Blust et al 2010). And third, there is a lack of consistency in reporting the LC/EC50 values as total, dissolved or monomericin the literature. Recent studies performed by the European Aluminium Association demonstrate that the only reliable predictor of toxic effects to aquatic organisms is total aluminium. This has been demonstrated across a broad range of pH, DOC and hardness values. Hence, for classification purposes we chose to use “total” Al (i.e., non filtered samples) in the test media as the most appropriate parameter for reporting LC and EC50 values.

 

 

 

Development of an Acute Ecotoxicity Reference Value (ERV)

 

There are two possible approaches for assessing the significance of T/D test results for classification: (1) the T/D test media at the end of the 7 or 28 day study can be used directly as the test media for the toxicity studies or (2) the amount of dissolved metal in solution can be compared with a toxicity test performed at the same pH using a soluble metal salt. For the first approach, if there is no toxicity, the substance would not classify and there is no need for an ERV as the test solutions are evaluated directly following the T/D test. For the second approach there is the need for an ecotox reference value. This value needs to be generated from the available (high quality) ecotoxicity data for fish, invertebrates and algae and are compared against dissolved metal concentrations at the end of the T/D study. 

 

Extensive testing recently performed with aluminium salts for purpose of developing an environmental quality standard (EQS) by the European Aluminium Association, has demonstrated that unlike cationic metals, total Al is a better indicator of toxicity than either soluble or monomeric Al. For purposes of determining the ERV, only studies which report total aluminium and which were of sufficient quality to be used in the BLM modeling of aluminium were used for classification purposes. Our review of existing and recently generated data indicates that toxicity does not correlate well with dissolved or monomeric Al. This suggests that most, if not all, the acute effects being observed are due to physical effects on the gills or respiratory membranes due to coating/smothering with aluminium hydroxide and does not reflect intrinsic toxicity. This is true even for studies receiving a Klimish rating of 1, i.e., the study was performed well and followed all the guidelines, but solubility was exceeded and hydroxide polymers were formed. Recognizing the limitations of these data and the extreme difficulty of deciding which data were sufficiently reliable for use or not for classification, we chose to evaluate the available acute data by developing BLM models for invertebrates, fish and algae using the best data available. The models were then used to generate LC/EC50 values under standard conditions, i.e., pH 6 and 8 with a hardness of 100 and a DOC of 2 mg/L. These water quality parameters are considered reasonably conservative values for classification purposes and mimic water quality in standard OECD test media. 

 

Table # " Ecotox reference values generated using acute BLMs for aluminium; hardness 100 mg/l and DOC 2 mg/l"

(below) lists the ERV developed for comparison against the CIMM T/D results for 7-day studies. The values generated for fish are from the BLM developed from the NIVA data (based upon Atlantic Salmon, most sensitive fish species).  The invertebrate and algae values were generated using multiple linear regression models (models developed based upon CIMM data). For the invertebrate model, pH 8 values were extrapolated since the model used pH 6 and pH 7 results because there was typically insufficient mortality in the pH 8 tests for C. dubia even thought the test concentrations were in the high mg/L range (i.e., EC 50 values are reported as the highest test concentration).

T/D data for 28 days are not discussed as Aluminium is highly insoluble at pH 6 and so is rapidly lost from the water column at neutral and alkaline pH values. Hence, the rapid loss from the water column argues for no chronic classification as agreed to by the C&L Committee.

Table #. Ecotox reference values generated using acute BLMs for aluminium; hardness  

100 mg/l and DOC 2 mg/l

                               

Species

EC 50 Value (mg/L): pH 6

EC 50 Value (mg/L): pH 8

Fish

1.15

4.07

Invertebrate

(Daphnids)

 

3.481

 

634.4

Algae

(Selenastrum capricornutum)

 

1.04

 

3.39

Final ERV

1.0

3.39

 

 

 

 

 

Transformation-Dissolution

 

 

The transformation / dissolution of aluminium compounds, powders and massive forms were tested by both by the Norwegian Institute for Water Research (NIVA) and the Chilean Mining and Metallurgy Research Center (CIMM).

 

NIVA:The NIVA report [Summary of 1996 Ecotox Studies NIVA] reports results of T/D studies followed by acute toxicity tests in the OECD T/D media. To be clear, the T/D media after 9 days of stirring was used as the test media (five concentrations and a control) for the toxicity tests. Aluminium oxide, hydroxide, powder (6 µm) and metal shavings were tested in T/D tests and the test media used with fish (Salmo trutta), daphnids (Daphnia magna) and algae (Selenastrum capricornutum). No toxicity was observed in any test or loading with the exception of one test with small Al powder, where the EC50 for algae was 1050 µg/L (1.05 mg/L). See Table # " Toxicity test result from the NIVA transformation-dissolution studies" (below).

 

               Table #. Toxicity test result from the NIVA transformation-dissolution studies

Species

Test Substance

Loading

LC/EC 50 (mg/L)

Measured [Al] at Maximum Loading

(mg/L)

Salmo Trutta

Al203

100

>100

0.074

D. Magna

‘’

100

>100

0.076

Selenastrum Capricornutum

‘’

100

>100

0.052

 

 

 

 

 

Salmo Trutta

Al(OH)3

100

>100

0.072

D. Magna

‘’

100

>100

0.005

Selenastrum Capricornutum

‘’

100

>100

0.003

 

 

 

 

 

Salmo Trutta

 

Al Powder

-

-

 

D. Magna

 

‘’

-

-

 

Selenastrum Capricornutum

 

‘’

1

1.05

 

 

 

 

 

 

Salmo Trutta

 

Al Metal Shavings

100

>100

0.084

D. Magna

 

‘’

100

>100

0.136

Selenastrum Capricornutum

 

‘’

100

>100

0.053

 

Classification Conclusions based on NIVA results: It is concluded that no acute classification is appropriate for Al oxide, Al hydroxide, and Al metal massive based on the fact that a loading of 100 mg/L was used in 9-day T/D tests that were at pH 8-8.5, i.e., pH where maximum solubility of Al is expected. No mortality was observed for fish, daphnids or algae at the highest levels tested (saturated solutions from the 100 mg/L loading TDP test). Toxicity was observed for the alga, Selenastrum Capricornutum in the test with the Al powder at a T/D loading of 1 mg/L; EC50 = 1.05 mg/L. Hence, this substance would classify by this test as Acute II. Following the CLP rules, the substance would not classify if there is no concern for long term toxicity, i.e., Acute II does not stand alone without the accompanying chronic classification. Since the loss rate of aluminium from the water column is known to be fast due to the formation of aluminium hydroxide precipitate at the pH range where toxicity is the greatest (i.e., pH 7.5-8.5), there is no concern for long term (chronic) toxicity – this was agreed to by the Classification and Labeling Committee in 1999 (see report 013-003-00-7 submitted to the C&L Committee, 1999).

 

 

CIMM: At CIMM, samples of a commercially available aluminium oxide and aluminium hydroxide were tested at 1 and 100 mg/l loadings at pH 6 and 8, two aluminium powders of different particle size were tested at 1 and 100 mg/L at pH 8 and aluminium wires as surrogate of massive forms (1 and 100 mg/L, pH 6 and 8) for up to 28 days at a stirring rate of 100 rpm. 

 

Al203– Aluminium Oxide

 

The maximum concentration in solution after 7 days was 0.082 mg/L at pH 8 and a loading of 100 mg/L. At pH 6, the maximum concentration in the TDP test solution was 0.005 mg/L (see Table below). These test concentrations are below the ERV (3.39 mg/L) and therefore aluminium oxide would not classify on an acute basis. Since the loss rate of aluminium from the water column is fast due to the formation of aluminium hydroxide precipitate, there is no concern for long term (chronic) toxicity – this was agreed to by the Classification and Labeling Committee in 1999. Therefore, there is no acute or chronic classification forAl203.

 

Al(OH)3Aluminium Hydroxide

 

The maximum concentration in solution after 7 days was 0.004 mg/L at both pH 8 and pH 6 and was not related to loading (see Table below). These test concentrations are below the ERV (3.39 mg/L) and therefore aluminium oxide would not classify on an acute or chronic basis.  Therefore, there is no acute or chronic classification forAl0H3.

 

 

Aluminium Powders

 

Two aluminium powders of different sizes and surface areas (<10 µm and 53-355 µm) were test for 7 and 28 days. For the small powder (<10 mu), at a loading of 1 mg/L the amount in solution at pH 8 after 7 and 28 days was 0.0720 and 0.310 mg/L, respectively (see Table 7.6.2 -3 below). Tests at pH 6 were not performed because of the very limited solubility at pH 6. After 7 days, at loadings of 1 and 100 mg/L, the measured concentrations were 0.723 and 0.857 mg/L, respectively. 

 

 

Large Powders:For the larger powder (55-355 mu) at pH 8, the amount in solution after 7 days at loadings of 1 and 100 mg/L was 0.084 and 0.713 mg/L, respectively (see Table 7.6.2 -3 below). It is concluded that the large powder (55-355 mu) does not classify for acute toxicity as the dissolution values are all below the ERV (3.39 mg/L). Since the loss rate of aluminium from the water column is fast due to the formation of aluminium hydroxide precipitate, there is no concern for long term (chronic) toxicity – this conclusion was agreed to by the Classification and Labeling Committee in 1999. Therefore, there is no acute or chronic classification.

 

Powders: The data at present indicate that the ability to use surface area release is confounded by formation of insoluble Al species and changing concentrations of Al species over time. Therefore, additional efforts to develop a critical surface area approach were abandoned.

 

Aluminium Massive

 

Aluminium massive was tested as pure aluminium wires. This approach allows for a calculation of the surface are exposed to the test media. The wires were tested with and without polypropylene wheels attached to the ends of the wires. The wheels have been shown to reduce abrasion with other metals (copper) during the T/D test. This was not the case with the Al wires and the data without wheels is presented. The resulting concentrations of Al were very low and below the ERVs at pH 6 and 8 as shown in the table below.

 

Table #. T/D results (7-days) for two Aluminium powders and massive aluminium (mg/L)

Substance

Endpoint

Endpoint

pH

ERV

(ug/L)

 

7-day - 1 mg/L

7-day-100 mg/L

8

3.39

Small powder

0.723

0.857

8

3.39

Large Powder

0.084

0.713

8

3.39

 

 

 

 

3.39

Wires/massive (w/o wheels)

0.017, 0.018

0.136

8

3.39

Wires/massive (w/o wheels)

0.003

0.006

6

1.04

 

 

 

 

 

 

 

 

 

 

References

 

Blust, Ronny, Peter Campbell and Claude Fortin. 2010.Assessing the risks associated with metals that change speciation and/or form precipitates under natural environmental conditions – comparison of chemical equilibrium models, Report to Industry Ecotoxicity Technical Assessment Panel (ETAP).

 

Euras. 2007.  Development of a high quality aquatic ecotoxicity database for Al metal, Al oxide and Al hydroxide, ARCHE Company, February 2007.

 

NIVA. 1996. Summary of 1996 Ecotox Studies. Effects of aluminium oxide, hydroxide, powder and metallic shavings on fish, daphnia and algae. Sponsored by the European Aluminium Association; issued by the Norwegian Institute for Water Research.

 

Rodriguez, Patricio. 2007.Final report to the European Aluminium Association OECD Dissolution Transformation Tests for aluminium hydroxide, aluminium oxide and metallic aluminium powder and massive forms. Chilean Mining and Metallurgy Research Center (CIMM). March 2007.

 

Van Gestel CAM, Hogerwerf G. 2001. Influence of soil ph on the toxicity of aluminium for Eisenia andrei in an artificial soil substrate, Pedobiologia 45: 385-395 ,