When I first began my journey in Occupational Safety and Health Administration [OSHA] compliance/infection control, I had a sense of some of what I thought I might run into, and a curiosity about those unexpected experiences that I might encounter.
Given OSHA’s compressed-gas standard and what they call their 5A1 General Duty clause in all of their standards, along with the presence of these very large cylinders of compressed-nitrous tanks on most of our premises, it is certainly reasonable for a compliance officer to require an air quality test for low levels of nitrous oxide. Compliance officers can ask you to have such a test done, or may conduct it themselves, if they have reason to believe that a problem exists. They may, for example, be alerted to a possible problem by complaints of an unusual number of infertility problems of a sort in a particular facility.
I have had the opportunity to be involved in approximately 100 nitrous air quality tests in dental offices. More offices than I would have believed or expected were mildly to excessively over the permissible limit.
Although some controversy exists, the most accepted reasonable limits on long-term exposure to low doses of nitrous oxide are 50 parts per million, or ppm, in the operatory during administration, and 25 ppm outside the operatory. In some cases, I found levels as high as 800 to 900 ppm.
Now, no need to panic. We aren’t all potentially dealing with this hazard. The operative words I used earlier—more offices than I would have believed—for me meant just one. Of the approximately 100 or so offices I’ve dealt with on this issue, maybe 6 to 8 percent were over the permissible limits. That’s approximately six to eight offices. That’s a good number of our personnel exposed to this hazard, and most of them are in their childbearing years.
In some cases, we tested twice to be sure before attempting to address the problem and found the first test had been accurate. The requirement then is to investigate and correct the alleged problems, and test again. Valves leak, solder joints in tubing in the walls give occasionally, lines are inadvertently juxtaposed during installation (it has happened), and, in one case, a nail was driven into a nitrous line in the wall.
So, are you feeling "unusually" happy at work lately? Sorry, but these doses, mildly or excessively over the permissible limit, do not provide you with clinical perception of the problem, and can have long-term consequences.
