Impurities and classification
Mark Selby
Denehurst Chemical Safety Ltd
mark.selby@denehurst.co.uk
www.denehurst.co.uk
Denehurst Chemical Safety Ltd
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Why classification ?
The purpose appears to be either to allocate specific
classification criteria to a substance or to
communicate potential hazards to users
1. Entry to C & L Inventory (Notification) or Registration
2. Presentation of SDSs and labelling and for transport
Can these acts be considered together or should
they be separated ?
Denehurst Chemical Safety Ltd
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CLP Notification / Registration
€ Need to be sure that the substance with the defined
EC number is correctly assessed for hazard and the
appropriate classification assigned
€ Testing may be performed on the pure substance
€ If varying results within an endpoint from different
sources of materials, can the differences be explained
€ Can the substance described in 1.1 of IUCLID be
properly assessed using reliable data
BUT....
Impurity details must be known
Denehurst Chemical Safety Ltd
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Equivalence ?
For registration, it is necessary to understand if data set
is applicable to your substance
€ Is the declared composition / purity / impurity data
‘equivalent’ to the material used for testing
€
Equivalence can be used for sameness or read-across
€ Have any impurities impacted on potential hazard ?
€
Declared in Section 1.2 of IUCLID and on CLP Notification
€ Different grades may be identified to recognise different
constituents in UVCB or multi-constituent substance
€ These ‘grades’ need to be linked with multiple classifications
€ When each grade is supplied, its identity must be made
clear in terms of which grade is being supplied
Denehurst Chemical Safety Ltd
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Classification for supply
The labelling and SDS for material being supplied must match
what is in container
Mixtures and impure substances can be treated the same
way
€ Classification is sum of hazards from pure substance
and the hazards of impurities
€ Apply same criteria as for mixtures
€ Suppliers are not expected to test mixtures
€ Therefore, are your expected to test impure substances ?
Denehurst Chemical Safety Ltd
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Conflicting purity
If two or more SIEF members have different purity range
/ impurity content
€
€
They should try to agree on range for registration
They must agree if studies are valid on the purities
€
Agreed classification should be for pure specification*
€
If material contains hazardous impurities, make estimation of
classification for supply based on same principles as mixtures
* For UVCB, multiple grades with multiple classifications may be the
only way to agree; otherwise, SIEF splits and different substances
registered.
Denehurst Chemical Safety Ltd
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Conclusions
Classifications for inventory (and therefore if
Notified under CLP or when registered) should be
for pure material if possible to determine
€
€
Same as applied to Annex I of 67/548/EEC and Annex VI of
CLP
For UVCB, different grades may be applied to each
be given classification
€
€
As with ‘notes’ in Annex I of 67/548/EEC for
petrochemicals
For supply and transport, the impurity may
influence classification and labelling
€
€
Treat like mixtures and identify hazardous impurity on
label / SDS
It will take years for harmonised classification to be
finalised – if ever !
Denehurst Chemical Safety Ltd
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