Airgas to Host Session on Selecting Gas Calibration Mixtures at PITTCON.

RADNOR, Pa. -- Airgas, Inc. (NYSE:ARG) will host a session on the methods for selecting gas calibration mixtures at the Pittsburgh Conference (PITTCON) on Tuesday, March 1, 2005 at 10:45 a.m. The presentation, one of four that Airgas will offer at the conference, is designed to help specialty gas users understand how to specify calibration mixtures for laboratory and process applications. Daniel Bartel, director of technical services, and Christopher Rowley, specialty gas market development manager, will speak.

"Gas calibration mixtures can be a source of anxiety for those responsible for buying and using them," Bartel said. "This presentation is designed to demystify calibration standards and help end users understand how they are made and measured."

Gas calibration mixtures, used by various industries to calibrate measurement instrumentation, can range from simple, two-component uncertified mixtures to complex, ninety-nine component hydrocarbon standards that are individually analyzed and certified. The session will cover all of the factors involved in manufacturing and certifying these mixtures, as well as the process of determining quality, accuracy and analytical certification of specialty gas blends. The oral session also will address:

--The importance of defining units of measure by mole, weight or volume for concentrations in various types of mixtures

--The difference between preparation tolerance and analytical tolerance

--Traceability of standards, including Standard Reference Materials (SRMs), NIST Traceable Reference Materials (NTRMs) and Gas Manufacturer Intermediate Standards (GMIS).

--Guidelines for EPA Protocol Gas Mixtures

--How to specify gas calibration mixtures from your vendor

As the U.S. leader in specialty gases, Airgas serves a variety of customers in the analytical and process industries. Over the past year, three Airgas specialty gas facilities in Riverton, NJ; Port Allen, LA; and Royal Oak, MI have earned ISO 17025 accreditation, the international standard for calibration and testing laboratories. The accreditations help ensure Airgas' ability to meet customer requirements for accuracy, precision and traceability.

Additional information on the sessions, as well as on Airgas specialty gas product and service offerings, will be available at Airgas booth #4301 during PITTCON, which runs from February 27 to March 4, 2005.

About Airgas, Inc.

Airgas, Inc. (NYSE:ARG) is the largest U.S. distributor of industrial, medical and specialty gases, welding, safety and related products. Its integrated network of about 900 locations includes branches, retail stores, gas fill plants, specialty gas labs, production facilities and distribution centers. Airgas also distributes its products and services through eBusiness, catalog and telesales channels. Its national scale and strong local presence offer a competitive edge to its diversified customer base. For more information, please visit www.airgas.com.