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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

oxidising solids
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because there are no chemical groups present in the molecule which are associated with oxidising properties and hence, the classification procedure does not need to be applied
Justification for type of information:
Assessment of oxidising properties:
Experimental techniques are available for classification of a substance or preparation as oxidising. These are described in EC test A17 (solids) and EC test A21 (liquids). However, Test A17 need not be carried out when examination of the structural formula establishes beyond reasonable doubt that the substance has no oxidising properties. The supplement to the A17 method describes situations in which experimental assessment of oxidising properties is not necessary. The contents of this supplement are outlined below.
Compounds which have no highly electronegative atom - oxygen, fluorine, chlorine, bromine - are not likely to possess oxidising properties. Similarly, where these elements are present but the atoms are only bonded to carbon and/or hydrogen, then oxidising properties are unlikely. A substance may have oxidising properties when:
• the electronegative atoms which are present constitute a high proportion of the molecule and are bound to elements in a high oxidation state;
• the electronegative atoms are bonded to each other or to electronegative elements such as iodine, nitrogen, sulphur or phosphorous.
As the ability to predict the reactivity of chemical compounds from their structure is still limited, the best approach is by analogy with existing compounds. A functional groups table provides a list of oxidising compounds and reactive groups which increase the oxidising power. However, this list is not exhaustive. If the substance meets one of the above criteria. The lack of any reactive group listed may not be sufficient to justify not performing the A17 test.
For organic substances only, the oxygen balance (OB) calculation may be useful as a criteria combined with an examination of the chemical structure as a mean of predicting oxidising properties. For organic substance CXHYOZ of molecular weight M, the OB is calculated as follows:
Oxygen balance = -1600(2X + Y/2 - Z) / Mol. wt.
Although experts think that the OB calculation is a possible approach, there is currently no consensus on the criteria that should be used. For the moment, judicial judgment will be required to use the OB value on a case by case basis. In any case, if theoretical considerations are used to exclude performance of the A17 test, the reasons and all relevant information should be clearly stated in the technical dossier.

Assessment of oxidising properties of sodium pentaborate:
Examining the structural formula, the following observations can be made:
The molecule does not contain any functional groups listed. Although this list is not exhaustive, this is a significant observation as most commonly occurring oxidising functional groups are contained within the list.
According to the two criteria quoted, oxidising properties can exist when:
• the electronegative atoms which are present constitute a high proportion of the molecule and are bound to elements in a high oxidation state. In the case of sodium pentaborate, the proportion of electronegative atoms in the molecule is high (17 oxygen atoms out of an overall atom count of 35). However, all oxygen atoms are bound to boron atoms.
• The electronegative atoms are bonded to each other to other electronegative elements such as iodine, nitrogen, sulphur or phosphorous. In the case of sodium pentaborate the electronegative atoms are not bound to one another, nor to any other electronegative elements.
Assessment against these two criteria indicates strongly that the molecule will not have oxidising properties.
In every respect of the oxidising solids exemption procedure, the material does not show any evidence of possessing oxidising properties.
On the basis of this exercise, the material should be considered as not oxidising and should not be subjected to experimental testing. The material meets all criteria for exemption from testing and has a structure not al all conducive with that required to exhibit oxidising tendencies.

Data source

Reference Type:
study report
Report date:

Materials and methods

Results and discussion

Applicant's summary and conclusion