Managing specialty gases and cryogenic liquids can create a variety of headaches and hassles for life sciences laboratories.
Selecting the right grades and quantity is not easy. Upon arrival, a gas supply system must safeguard purity to the point
of use. Labs also need to maintain enough cryogens, like liquid nitrogen, carbon dioxide, and dry ice, to preserve their work.
Yet cryogens vaporize over time. Add the challenge of returning empty cylinders and the supply chain looks pretty complex.
This article focuses on how to buy and manage both gases and cryogens, and offers potential remedies and cost saving measures.
A future article in BioPharm will concentrate on gas mixtures and gas stream purity.
For every dollar spent on gases and cryogens, most users spend two to three dollars on inefficiencies in gas selection, storage,
handling, administration, waste, and downtime. Addressing these issues can add up to real savings.
SPECIFYING THE RIGHT PRODUCT
Life sciences laboratories have several analytical applications that require carrier, makeup, and fuel gases for gas chromatography
(GC) and other equipment, as well as sample storage applications that require liquid cryogens and dry ice. Scientists often
specify the names and grades of product they need. However, with few exceptions, there are no industry standards for name
or grade specifications. One supplier's "300-size, zero-grade helium" may be very different from another's "300-size, zero-grade
helium." In fact, there are no standards for defining what constitutes a zero-grade gas. A researcher may assume that zero-grade
helium means the gas is "five-nines" or 99.999 percent pure. However, a review of the product specifications from gas suppliers'
websites indicates that no major specialty gas supplier offers zero-grade helium that is 99.999 percent pure. Instead the
range of purities was 99.995 to 99.998 percent; one company no longer even offers zero-grade helium.
In the life sciences, there are important exceptions. In order to call a gas a medical grade, it must meet certain Food and
Drug Administration (FDA) regulations. Other specialty gases must meet United States Pharmacopeia or National Formulary (NF)
standards. In addition, some emissions monitoring standards must meet strict rules outlined by the Environmental Protection
Agency or other regulatory bodies. Yet, these are the exceptions. Most gases used in biotechnology laboratories fall into
this general rule: the lack of a universal standard for defining gas grades and names makes selection of the correct gas a
complex process. Users who select gas by name alone can end up with poor gas selections.
Some biotechnology and pharmaceutical companies needlessly restrict their options and increase costs by writing inappropriate
specifications into their standard operating procedures in a misguided attempt to placate FDA. By specifying a manufacturer's
product name or grade for carrier gases on a GC used in quality control analysis when such specificity is not required, companies
are limiting their options. The key is to understand the specificity required based on the application and then to source
it from a reliable organization.
Insulated gloves approved for use in cryogenic service must be worn when operating valves or when the potential exists for
human contact with product or exposed cold piping.
The "purity paradox" adds further confusion. Many chemists want the purest gas — gas that is 99.999 percent pure. Instead,
they should consider specific impurities that could affect a specific application and then determine the quantity of impurities
that can be tolerated without hindering analytical results or adding to operating costs.