Phosgene, also known as Carbonyl Chloride, is a widely used but highly toxic substance. At room temperature Phosgene gas is nearly colourless, and at low concentrations cannot be smelled. This hazardous substance is used in a variety of chemical reactions, especially in organic syntheses, such as in the manufacturing process of Di-Isocyanates, Poly-urethanes and Polycarbonates.
Millions of tons of Polycarbonates are manufactured every year. CD-ROMs and DVDs are just two of many examples of common products made of Polycarbonate.
Strict safety and security provisions minimize spectacular and large scale accidents. However, persons involved in chemical production, health and safety surveillance or first response action forces are well aware of the potential dangers of a Phosgene exposure. When it comes to dealing with hazardous substances in a working environment, industry and authorities demand precise monitoring to protect personnel, facilities and neighbouring residents
A creeping danger
A potential scenario during routine operations is the presence of very low concentrations of the toxic chemical. No gas alarm will be triggered, as the Phosgene concentration itself stays below threshold values. However, a person working in an exposed area all day long or for several days in a row could well receive a cumulative dose that exceeds admissible levels. The cumulative dose is the sum of all the tiny contributions during the day or days.
Harmful consequences of Phosgene
The medical consequences of an excess Phosgene dose can be severe. Damage to the respiratory tract and the bronchioles can result in pulmonary oedema that may ultimately affect the heart. The heart becomes overworked in an attempt to supply oxygen to the body. Typically, the first symptoms occur several hours after exposure. For that reason, accurate information about the nature of a possible incident and the person's exposure characteristics is of the highest importance.
Health protection requires reliable monitoring and accurate dosimetric devices
Conventional methods include paper badges that change colour and turn red (or sometimes blue) when exposed to Phosgene. To work properly and indicate the dose reliably, the paper badge must be stored in airtight containers before use. After the work shift, if the paper badge was exposed to Phosgene, the safety co-ordinator applies a colour comparison chart to figure out whether the exposure was above or below threshold. If no colour change was visually detected, usually the paper badge is thrown away. Obviously with the disposal of the badge, any record of an incident would be gone as well. Any chances to investigate an incident in retrospective are gone.
In addition, the use of colorimetric paper cannot differentiate between an incident of short duration or one that has accumulated from lots of small contributions over a specified time interval. It makes a difference whether a dose was from a short duration and high concentration or whether the overall dose was recorded during an eight-hour-shift.
In-depth dose profiles and immediate warning for the user
MST Technology's inno-badge is an important step forward in health and safety protection. Conventional methods do not reflect the important history-profile of a gas exposure. The inno-badge makes in-depth gas concentration profiles accessible. The individual exposure history is measured and recorded electronically. The data can be then analyzed by a health and safety coordinator. “It's the ability to count and record the dose history in full detail, and with a highly reliable electronic device, that makes the most significant difference of the inno-badge to conventional methods,” stresses Dr. Elisabeth Wasserle, product manager at MST Technology and responsible for the forthcoming market launch of the inno-badge. Important information will no longer be thrown away with paper badges that, for whatever reason, did not show a colour change. The inno-badge is a small, light, and durable device that will revolutionize the way gas concentration data are recorded for the sake of personal protection. And – even more important –the inno-badge will warn the user immediately as soon as an excess Phosgene dose is registered.
Task of checking your dose made personal
With conventional methods workers must check their own badge regularly or depend on their colleagues to warn them of any colour change. For persons working in an environment with a risk of Phosgene exposure, an alarm function with pre-set alarm levels for peak concentration and integrated dose is a great relief. “This is why the inno-badge features a visible, audible and upon request, a vibration alarm. The programmable alarm threshold values can be set individually, according to national regulations and company policies,” explains Wasserle.
Maximum ease of use
The inno-badge is small, rugged and simple to handle. Simply push the start button and the inno-badge is ready for use for 90 days. There is no need to worry about calibration or complex set-up procedures. Self-test routines are executed automatically. A short instruction is sufficient to familiarize anyone with the operation of the inno-badge. The LCD displays the remaining life time of the sensor, and a blinking heartbeat symbol that confirms that the inno-badge is active.
Health and safety co-ordinators can quickly configure and hand out inno-badges. Concentration data can be retrieved and downloaded to a PC when the unit is returned at the end of a shift or after the life span of the unit. Data is permanently recorded for immediate or future analysis. Each inno-badge provides as standard data sets a comprehensive dose history log-file as well as running 12 to 72 hour averages of the measured Phosgene concentration. The readout can be stored, viewed and analyzed with prevalent software applications
Meeting industry demand with an innovative concept
With the development of the inno-badge MST Technology has successfully applied the essence of 15 years of experience in electrochemical sensor technology to the field of personal protection. “Demand for the concept originally comes from the chemical industry,” stresses Dr. Wasserle. “The idea to use our tried and tested electrochemical sensor technology in this new field has encouraged us to develop the innovative two part design of the inno-badge with its advanced features. With the inno-badge our highly reliable and accurate measurement technology will soon be available for personal and environmental protection.”
MST Technology GmbH