Assessment of Classification Variability Resulting From the VMG Validation Exercise for Dicopper Oxi

1
Assessment of Classification Variability
Resulting From the VMG Validation Exercise for
Dicopper Oxide, Nickel Powder, Tetracobalt Oxide
and INVAR Alloy Presented to OECD September 28,
2006
1Bill Adams, 2Jim Skeaff and 3Patricio H.
Rodriguez 1Rio Tinto 2CANMET 3CIMM
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Introduction

• OECD transformation dissolution protocol
  validation was performed at 4 laboratories
  (CANMET, CIMM, LISEC, ECVAM)
• Three loadings, two pH values were used
• Results are presented in terms of classification
  outcomes consistent with the GHS aquatic
  classification system for sparingly soluble
  metal substances
• Inconsistent classification outcomes are
  identified for discussion

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GHS Aquatic Classification Categories1
1 Classification categories relate to label
warnings
4
Ecotox Reference Values (ERV)

• ERVs were agreed upon by the EU Classification
  and Labeling Committee TCNES (dicopper oxide,
  iron) or reported in EU risk assessment (nickel)
  and agreed to by reviewing country (Denmark) or
  resulting from ecotox testing (cobalt tetraoxide)
  to be used for REACH.

ACR estimated Acute to Chronic ratio cobalt
final chronic value is under development.
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Evaluation of T / D Ring Test Results
Ring Test Outcomes (following tables)
Yes means the amount of metal in solution on day
7 exceeded the Ecotox Reference Value (ERV)
No means metal in solution did not exceed the
ERV and therefore would not classify at the given
loading
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Evaluation of T / D Ring Test Results
Ring Test Outcomes (following tables)

• OECD decided
• that Lab 4 test results were not valid for
  purposes of the ring test
• The variance in the test data for the remaining
  three labs was low.

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Evaluation of T / D Ring Test Results
Ring Test Outcomes
A review of the classification outcomes was
prepared as a means to assessing consistency
between laboratories
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Acute Classification Assessment for Dicopper
Oxide 7 days (ERV 29 µg/L)
Supporting dissolution data
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Acute Classification Assessment for Nickel
Powder 7 days (ERV 68 µg/L)
Supporting dissolution data
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Acute Classification Assessment for Cobalt
Tetraoxide 7 days (ERV 6.7 µg/L)
Supporting dissolution data
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Acute Ecotox Reference Values (ERV) for INVAR
Alloy
For this initial exercise, classification was
assessed by comparison with the individual
Substance ERV and not its toxic unit fraction.
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Acute Classification Assessment for INVAR Alloy
Nickel. (ERV 68 µg/L)
Supporting dissolution data
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Acute Classification Assessment for INVAR Alloy
Cobalt. (ERV 6.7 µg/L)
Supporting dissolution data
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Acute Classification Assessment for INVAR Alloy
Iron. (13.3 mg/L)
Supporting dissolution data
15
Overall Acute Classifications 4 Labs
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Overall Acute Classifications 3 Labs(Without Lab
4)
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Chronic Classification Assessment for Dicopper
Oxide 1 mg/L loading, 28 days (ERV 8 µg/L)
Supporting dissolution data
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Chronic Classification Assessment for Nickel
Powder 1 mg/L loading, 28 days (ERV 2.4 µg/L)
Supporting dissolution data
Values are equivocal
Values are Much higher
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Chronic Classification Assessment for Cobalt
Tetraoxide 1 mg/L loading, 28 days (ERV 2.3
µg/L)
Supporting dissolution data
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Chronic Classification Assessment for Invar
Alloy Nickel. 1 mg/L loading, 28 days (ERV 2.4
µg/L)
Supporting dissolution data
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Chronic Classification Assessment for Invar
Alloy Cobalt. 1 mg/L loading, 28 days (ERV 2.3
µg/L)
Supporting dissolution data
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Chronic Classification Assessment for Invar
Alloy Iron . 1 mg/L loading, 28 days (ERV 1000
µg/L)
Supporting dissolution data
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Overall Chronic Classifications
Note for this assessment the chronic
classification (Chronic IV) was used and was not
linked to the acute classification as would be
done in regulatory application.
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Overall Chronic ClassificationsWithout Lab 4
Note for this assessment the chronic
classification (Chronic IV) was used and was not
linked to the acute classification as would be
done in regulatory application.
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Conclusions

• Acute Classification Outcomes
• Out of a potential of 72 classification
  possibilities (excluding INVAR Alloy) at loadings
  of 1, 10 and 100 mg/L
• three of the four labs agreed in every case but
  one
• For the Alloy, assessing each metal component
  separately
• out of 72 classification possibilities
• three of the four labs agreed in all cases but
  two.

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Conclusions

• Chronic Classification Outcomes
• Out of a potential of 24 classification
  possibilities (excluding INVAR Alloy) at a
  loading of 1 mg/L
• three of the four labs agreed in every case but
  two
• For the Alloy, assessing each metal component
  separately
• out of 24 classification possibilities
• three of the four labs agreed in all cases

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Conclusions

• Question
• Can we agree that the TD / P is a useful method
  for assisting with metal classification?
• Should this method be used for alloys?