Munich, 21 May 2012: Linde Gases Division, a member of The Linde Group, has been awarded the US Environment Protection Agency’s (EPA) Photochemical Assessment Monitoring Stations (PAMS) contract for 2012. It is the 14th consecutive year that Linde will supply the US EPA’s ozone monitoring program with highly specialised calibration gases.
During the ozone season (typically May to September), the US EPA monitors persistently high ozone levels, which are mostly found in large metropolitan areas. To do so they employ ambient air monitoring sites, which collect and report detailed data about volatile organic compounds, nitrogen oxides, ozone and meteorological parameters. Analysis of the data helps the US EPA to better understand the underlying causes of ozone pollution, to devise effective remedies and to measure environmental improvement.
The contract requires the timely supply of multiple cylinders containing a highly specialised calibration gas mixture comprised of 57 different gases. It is crucial that the cylinders be delivered on time as data can only be collected during the hot summer months when the gases in the air are at their most volatile and reactive, and therefore most harmful to the ozone layer. The extremely sensitive gas mixture requires highly sophisticated technical and analytical know-how in order to guarantee the stability of components with concentrations as low as 3 parts per billion (ppb). Additionally, it is necessary to use a proprietary inert barrier to coat the inner cylinder wall to prevent contamination of the sensitive mixture.
“This contract is testament to our technical competence and makes us one of an elite number of organisations that can supply sophisticated specialty calibration gas mixtures of this nature on a consistent basis,” said Michael Hayes, Product Manager US EPA Protocols, Environmental and VOC Mixtures, Linde Gases Division. “As the world leader in specialised gas mixtures to help monitor our impact on the ozone layer, our team’s vast technical know-how is unparalleled.”
Linde is trusted to provide quality and stability of supply. Each cylinder is stringently analysed for component concentrations and lot homogeneity (required to be within 10 percent), before being sent to end users at the monitoring sites.
Businesses using solvents or incinerating waste, either for energy or waste disposal, emit the types of gases included in the monitoring programme. As such, the data is of interest to a wide range of industries, including petrochemical processing, textile and paper printing, waste disposal and solvent manufacturers.
Outside of the US, Linde’s PAMS mixture has also been used in China and Taiwan. The use of highly specialised calibration gas mixtures for environmental monitoring is becoming increasingly important in emerging economies and is set to grow as the World Meteorological Organization (WMO) looks closer at ozone depletion standards.