Linde Gases has achieved ISO 17025 accreditation for its specialty gases mixtures used for the environmental testing of volatile organic compounds (VOCs), and in doing so has ‘raised the bar yet again’ in gaseous standards for VOC detection.

VOCs are insidious and highly noxious chemicals that exist within the ambient air – both in the outdoor environment and within buildings.

Many are carcinogenic in nature and are directly attributable to serious human health problems, including diseases of the respiratory tract, even when exposure is limited to very low levels.

Additionally, when VOCs emitted into the ambient air react with nitrogen dioxide, a common pollutant from automotive emissions and other combustion processes, they form ground level ozone. Ozone is a powerful oxidizing agent, exposure to which has been associated with adverse health effects including asthma and decreased lung function. 

While many liquid VOC standards have been previously certified, this is the first time any industrial gases company has achieved such validation for VOC mixtures in a gaseous state – and in so doing, Linde has enabled a significant leap forward in legal metrology. 

Mike Hayes, Head of Premium Specialty Gases at Linde, reflected, “During the US energy crisis in the 1970s, a trend emerged to seal up buildings and make them airtight.”

“In the process that kept a lot of VOCs trapped within office environments – from copier toners, carpet fibers, and plastics and adhesives used in furniture manufacture – and they have been making people sick.”

“This ISO 17025 accreditation proves our technical competence in manufacturing these gaseous standards,” continued Hayes. “However, the fact that we are scoring significant numbers of commercial contracts for these environmental standards – including our 15th consecutive contract with the US EPA - elevates this accreditation announcement beyond the realms of theoretical excellence to a badge of confidence we wear daily.”

The international accreditation of Linde’s gaseous VOC standards is likely to have a significant impact on legal metrology – or the science of measurement as laid down by law. Cases involving environmental matters could often be dismissed due to the measurement standards used being contested. Linde can now provide that undisputable, known standard which can be held up in a court of law. Additionally, regulatory authorities will have the baseline guarantee needed to effectively write legislation requiring VOC testing to this level of quality.

Stephen Harrison, Global Head of Specialty Gases and Specialty Equipment at Linde, added, “With this accreditation, Linde has raised the bar yet again for gaseous standards for VOC detection. Until now, one could argue that there existed a level playing field of imprecision for gaseous standards used for legal metrology purposes.”

“To explain further, there was never anywhere to plant a flag in order to state what 1 part per million (ppm) of benzene, for example, actually looked like. Through years of technical innovation and advanced analytical and blending methods Linde has become the first to develop traceability procedures to prove 1 ppm of benzene – or indeed any other VOC – in a gaseous state, and guarantee a previously unattained level of precision.”

With ever-increasing environmental testing around the world, there are a growing number of federal and state agencies demanding an unequivocal ‘baseline’ or ‘anchor’ standard for VOC samples against which laboratories can reliably compare the samples they have for analysis.