About the customer
Dental practice, Dover, England
Challenge the customer faced
A dental engineer was sent to investigate N2O problems at the dental surgery after complaints from staff about the effects of the gas. Previous passive monitoring in the surgery had indicated a time weighted average (TWA) of N2O at 90ppm, and a suspected leak in a faulty machine. The machine was sent to be repaired, however staff continued to notice the effects of N2O.
The Geotech product
The G200 is designed to monitor background and breathing zone levels of N2O in medical environments. It can measure N2O at 0-1,000ppm and can calculate time weighted averages, as well as EH40 occupational exposure limits; it can also be used for N2O leak detection.
The G200 product in use
Using a G200 N2O monitor supplied by Bedfont Scientific, the engineer identified a leak from faulty sedation equipment. He also used another two G200s for staff to monitor their TWA. The engineer said: “I had three G200 monitors and set one up to monitor the area around the machine and then asked the dentist and nurse to wear one each on ‘person mode’. We monitored throughout the morning, including doing treatments using that machine. At midday I checked the readings and the area monitor was at 220ppm average, the dentist’s monitor was at 105ppm and the nurse’s was at 67ppm: very high readings for such a short period. I then set the area monitor onto ‘leak mode’ and used it to ‘sniff’ around the machine with it set to deliver 20% N2O at a low flow rate with the scavenger and delivery circuit connected. I found that the air intake of the mixer head on the machine was spewing out N2O – the readings went up to over 4,000ppm!”. These findings were reported to the sedation equipment supplier who confirmed that a valve inside was most likely faulty and they would issue a replacement. The surgery now has their own G200 monitor so they can easily keep a check on their equipment and they are planning to roll out a monitoring program to cover all of their sites in due course.