The venerable Mercury thermometer has been on its way out for a number of years and the National Institute of Standards and Technology next month may give it a final push.
On March 1, NIST said it will no longer provide calibration services for mercury thermometers. The cessation of the mercury thermometer calibration program marks the end of an era at NIST, which has provided the service since the doors opened in 1901. In fact NIST itself at one point had a stockpile of more than 8,000 industrial-use mercury thermometers hidden away in drawers.
The mercury from these has been sent to specialized recycling centers, which repurpose the mercury to produce compact fluorescent light bulbs. Mercury thermometers contain about 500 milligrams of mercury-an amount equal to the mercury in over 125 compact fluorescent bulbs, NIST stated.
The NIST announcement is only part of a world-wide effort to eliminate the use of Mercury. According to NIST, Mercury is a potent neurotoxin. Elemental mercury is found in thermometers and used in a number of industrial processes such as gold mining. Once released into the environment, mercury makes its way into streams, rivers, and finally the ocean. The mercury is absorbed by sea life and accumulates in the larger fish that humans like to eat. This is the main source of mercury poisoning in humans today, NIST stated.
According to the EPA, industrial and manufacturing measurement and control devices, including glass non-fever thermometers, still use mercury-containing products, but in many cases effective non-mercury alternative products exist. Presently about 300 of the approximately 700 standards have been amended to allow for the use of both mercury-free liquid-in-glass and digital thermometers.
According to NIST researcher Dawn Cross, each of these ASTM standards is reviewed on a rolling basis. She estimates that all the standards will have been amended to include detailed procedures for making the switch to mercury thermometer alternatives within three years.
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