ASTM and the Mercury Initiative
Standards and Mercury Instrumentation
Mercury, a metal whose Greek name means “water silver” because it is liquid at room temperature, occurs naturally in air, water and soil. It is an element defined as toxic and poisonous; it also possesses properties that make it consistently responsive to temperature change, making it a choice for thermometers, switches and some light bulbs.
Because of mercury’s documented health risks, 17 U.S. states have banned its transport and sale; the U.S. Environmental Protection Agency, in its “Roadmap for Mercury,” states that its long-term goal is to reduce those risks; and various groups are working to reduce mercury in processes and products.
As part of these initiatives, state administrators in 2006 petitioned ASTM International to reevaluate standards including instrumentation using or referencing mercury. Those standards total 853 consensus documents from 94 different technical committees.
In response to the petitions, ASTM International became part of a mercury removal initiative group started by EPA in response to a request from the Environmental Council of the States. In addition to EPA, ECOS and ASTM, the group includes the Northeast Waste Management Officials’ Association, the Quicksilver Caucus and laboratory accreditation agencies such as the American Association for Laboratory Accreditation.
“The overarching goal of the group is to reduce the use of non-fever mercury-filled thermometers for laboratory testing and industrial processes,” says Dean Ripple, Ph.D., group leader, NIST Thermometry Group, Gaithersburg, Md., a member of ASTM International Committee E20 on Temperature Measurement and a member of the mercury removal initiative group. In most cases, Ripple adds, there are good substitutes for such thermometers.
EPA’s Maria Doa, Ph.D., director, National Program Chemicals Division, Office of Pollution Prevention and Toxics, has been very involved with the mercury removal initiative group. She says that the group wants to identify good alternatives for mercury instruments where possible. “It’s very important to take the multi-faceted approach that is needed to get to the phasing out of mercury thermometers where there are substitutes. I really do believe that the different people who participate are really crucial to getting there. Having NIST involved, and ASTM involved and the states involved as well as the different parts of EPA, I think, is very important.”
Thermometer Use in the Oil and Gas Industry
Specific industry applications continue to call for the use of mercury thermometers. The custody transfer of oil and natural gas, for example, commodities that are bought and sold by volume at a stated temperature, require regular field temperature measurements to verify quantities. In such situations, “mercury thermometers remain the ‘gold standard’ even today because of their reliability,” says David Miller, P.E., director, API standards, at the American Petroleum Institute in Washington, D.C.
“Mercury thermometers are used because they are responsive, reliable, safe and easy to maintain. Once verified and/or certified traceable to NIST, the mercury thermometer is the most reliable device made. It either works or it does not and a simple inspection can determine if it is working properly,” Miller says. Miller notes that when temperature measurement devices are used for calibrations and measurements in the field, the environment may involve potentially flammable atmospheres and liquids that can accumulate static charges, and safety becomes an issue. Because mercury in glass thermometers have no electrical safety issues and are inherently safer than alternative devices, they will be used for such purposes until an alternative is felt to be trustworthy and safe.
Mercury and ASTM Standards
Each ASTM standard that references mercury must be considered individually for possible revision and the substitution of alternatives, and where other temperature measurement devices replace mercury instruments, method precision and bias statements must also be revised. To provide guidance about temperature measurement devices and their use in ASTM standards, technical committees can turn to an E20 task group led by Deanne Emory, owner and president of Miller and Weber in Ridgewood, N.Y.
Emory says, “The goal of our task group is to assist the different technical committees in deciding whether alternative temperature measurement devices exist to replace the currently required mercury ones without losing precision of their test methods and/or affecting their precision and bias statements.” Thus far, the task group, which has developed a caveat about the hazards of mercury for committees to use, has presented information to Committees D02 on Petroleum Products and Lubricants, D04 on Road and Paving Materials, D05 on Coal and Coke, and D18 on Soil and Rock.
Emory welcomes the opportunity to answer any questions. “Come to us,” Emory says. “If I can’t answer the question, I’m more than happy to send people to the other technical experts that are on my task force. We have people who are experts in all the different types of temperature measurement devices.”
For more information about the mercury removal initiative, contact Christine DeJong, ASTM International (phone: 610-832-9736).
For more information about the E20 task group and its available assistance for ASTM committees, contact Deanne Emory (phone: 718-821-7110).