Dipotassium tetraborate

Oxidising properties

Administrative data

Endpoint:

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 oxidizing properties
Experimental techniques are available for the classification of a substance or preparation as oxidizing. These are described in EC Test A17 (solids) and EC Test A21 (liquids0. However Test A17 need not be carried out when examination of the structural formula established beyond reasonable doubt that the substance has no oxidizing properties. The supplement to the A17 method describes situations in which experimental assessment of oxidizing 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 oxidizing properties. Similarly where these elements are present but the atoms are only bonded to carbon and/or hydrogen the oxidizing properties are unlikely. A substance may have oxidizing 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 other electronegative elements such as iodine, nitrogen , sulphur or phosphorus.
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. The table below provides a list of oxidizing compounds and reactive groups which increase the oxidizing power. However this list is not exhaustive. If the substance meets one of the above criteria, the lack of any reactive group named in the table 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 means of predicting oxidizing properties. For an 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, professional 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 on the A17 test, the reasons and all relevant information should be clearly stated in the technical dossier.

Assessment of oxidizing properties of dipotassium tetraborate.
Examining the structural formula, the following observations can be made:
•The molecule does not contain any functional groups listed in the table below. Although this list is not exhaustive, this is a significant observation as most commonly occurring oxidizing functional groups are contained within the list.
•According to the two criteria quoted, oxidising properties can exist when:
oThe 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 dipotassium tetraborate, the proportion of electronegative atoms in the molecule is high (11 oxygen atoms out of an overall atom count of 25) but all oxygen atoms are bound to boron atoms.
o The electronegative atoms are bonded to each other or to other electronegative elements such as iodine, nitrogen, sulphur or phosphorus.
 In the case of dipotasisum tetraborate the electronegative atoms are not bound to one another, nor to any other electronegative elements.
o Assessment against these two criteria strongly indicate that the molecule will not have oxidizing properties.
In every respect of the oxidizing solids exemption procedure, the material does not show any evidence of possessing oxidizing properties.
On the basis of this exercise, the material should be considered as not oxidizing and should not be subjected to experimental testing. The material meets all criteria for exemption from testing and has a structure not at all conducive with that required to exhibit oxidizing tendencies.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010