The volatile organic compounds (VOC) and Penetrant Testing/Magnetic Testing (PT/MT)

April 2009

We received an email from a European reader, about the VOC and our DPCNewsletter n° 011.
It comes as follows (edited for clarification):
"Hello Patrick,
Just read your DPCNewsletter n°011 about VOC's, etc.
Are you aware there is already a new Directive 2004/42/CE replacing 1999/13/CE? The vapour pressure is no longer the basic but it is the initial boiling point: products boiling at less than 250°C (482°F) are VOC, while those with a higher initial boiling point are not.
Bye
T.D."

We warmfully thank this reader for the information. In fact, it does not tremendously change the classification: the higher the boiling point, the lower the vapour pressure at 20°C, with very few exceptions.

For instance an hydrocarbon very often used as a basis for red dye penetrants formula or for oil-based magnetic testing particles, having a vapour pressure of 10 Pa, hence being a VOC as per the previous regulation, is still a VOC, as its boiling point is in the 230/270°C (446/518°F) range.

This applies also to the "white-spirit" mentioned in the DPCNewsletter: its boiling point is in the 135/220°C (275/428°F). Then it is a VOC ... but shall not be used as a degreaser prior to PT!