Understanding Custom Air Gas Mixtures

A custom air gas mixture is a precision-blended specialty gas where one or more target components — such as CO, NOx, VOCs, or formaldehyde — are combined at defined concentrations (PPB to percent levels) with a balance of synthetic air or nitrogen. These mixtures are formulated to exact customer specifications for calibration, monitoring, or research applications.

NIST traceability ensures that the concentration values certified on your calibration gas cylinder are linked to nationally recognized measurement standards maintained by the National Institute of Standards and Technology. This chain of traceability is required by regulatory agencies such as the EPA and OSHA and is essential for defensible emissions monitoring, workplace safety compliance, and analytical instrument accuracy.

SpecGas Inc. offers nitrogen, synthetic zero air, helium, and other inert gases as balance options for custom mixtures. The choice of balance gas depends on the analytical method, instrument type, and regulatory requirement. For example, air-balanced mixtures are commonly used for ambient air monitoring, while nitrogen balance is preferred for many reactive gas calibration applications.

SpecGas produces custom gas mixtures across a wide concentration range — from sub-PPB levels up to 10% or higher by volume. Typical calibration concentrations span 1 ppm to 100 ppm for most reactive and toxic gases, with PPB-level mixtures available for ultra-trace applications such as atmospheric monitoring and FTIR stack testing per EPA Method 320.

SpecGas supplies custom air gas mixtures in disposable aluminum and steel cylinders (17–103 liters gas capacity), refillable high-pressure aluminum and steel cylinders, and nickel-plated cylinders for reactive or corrosive gases. Specialty-treated aluminum cylinders are used for reactive gases such as formaldehyde and HCN to ensure stability throughout the shelf life of the mixture.

Custom air gas mixtures serve environmental emissions monitoring (EPA CEMS, stack testing), industrial hygiene and workplace safety (OSHA/NIOSH compliance), gas detector and analyzer calibration, semiconductor manufacturing, research and university laboratories, oil and gas operations (LDAR, wellsite monitoring), wastewater treatment, food processing, and pharmaceutical manufacturing, among many others.