TOPIC: Deceptive Practice/Industrial Hygiene Air Studies
Deceptive Practice/Industrial Hygiene Air Studies 12 years 10 months ago #1
If you've ever been humiliated by an industrial hygiene report done where you work that said \"nothing there\", read on...
I became very ill working with an industrial detergent used to clean medical equipment in a mechanized process that dumped this detergent, HOT, down an open pipe to an open \"floor sink\" drain. This detergent was full of glycols, one of which turned out to be phenoxyethanol (which is what gave me MCS). Needless to say, some very simple laws of physics dictate some vapor must be generated by this type of operation! The detergent waste falling down the open pipe caused a draft over the large surface area of the interior of the pipe... The water trap below the floor sink prevented this draft from entering the sewer and vapor and/or aerosol escaped to room air out the air gap at the drain.
My employer was very concerned and sympathetic, and ordered a study of the problem by a private (certified) Industrial Hygienist. When his report came back \"Nothing within the limits of detection\", my concerned and sympathetic employer reluctantly assumed I was a NUT CASE and asked me to sign a confidentiality statement that I would not speak of this matter again! It took a year of digging to find out what was going on. Here's what I learned.
While OSHA and NIOSH (government) methods use advanced and sensitive (extended sorbent sampling) in their air studies, private industrial hygienists (at least this one) typically utilize \"electronic noses\"... Little Star Trek/Tricorder like, hand held \"direct read\" devices. These devices are advertized as being very accurate by their manufacturer and the hygienists who use them. There's just one little problem... CALIBRATION.
When the manufacturer rates these devices for limits of detection, they calibrate them using highly purified, (Aadco?) air, after which they are highly sensitive to VOC and show a very good limit of detection, which is then published, advertized, and accepted as the limit of detection for the device.
In the field, these instruments are calibrated or \"zeroed out\" using a little charcoal filter that snaps on the intake of the device. The problemo occurs here, if everything doesn't work out perfectly; which studies have shown it often does not. When these charcoal filters are fresh off the assembly line (which is how they are tested), they can potentially filter out nearly all VOC from most sources, but once they are allowed to absorb moisture from the air, they lose a lot of their absorbent potential for VOC during calibration.
A calibration filter in this state allows VOC to get through... The machine is then zeroed by the operator, in effect telling the machine the VOC it is reading is actually zero! When the filter is removed, the machine then dutifully shows the difference in VOC between calibration and open sampling. If the air in the room is contaminated with VOC, there will be a reading... It will just be deceptively LOW.
In one performance evaluation of these instruments, the technicians reported the instrument actually read NEGATIVE VOC (less than zero!), when, after calibration with a charcoal filter, the instrument was switched to Aadco air!
If the industrial hygienist is hired \"private pay\" by the employer, and wants to do work for that employer again, he may describe a minimal reading as \"nothing within the limits of detection\" rationalizing a minimal read as nothing potentially dangerous anyway... If the hygienist were to report any finding of VOC, that would raise the question of \"what is it\"? This would require additional and expensive testing to identify the offending VOC, which employers don't like to hear, and many private hygienists don't like to report to the folks who pay their handsome fees. OSHA is very generous in their allowances for VOC, so many don't see a big problem with fudging a couple parts per million into a negative read on the report.
Even a zero tolerance (good!) hygienist willing to report any hint of VOC may not be able to read levels of VOC that can cause problems in \"potentially sensitive subpopulations\" using direct read instruments in the field. On a good day, the limit of detection for field calibrated direct read instruments may be accurate only down to around one part per million, while indoor air quality problems can often occur in the lower single digit parts per BILLION!
The moral to this story is... Private industrial hygiene surveys are generally worthless when it comes to non industrial indoor air quality problems... Don't ask for one, unless you want to be proven a \"nut case employee\" to your boss.
Post edited by: bolam56, at: 2008/03/03 03:46
Post edited by: bolam56, at: 2008/03/03 05:03
Post edited by: bolam56, at: 2008/03/03 05:04<br /><br />Post edited by: bolam56, at: 2008/05/24 00:43
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Re:Deceptive Practice/Industrial Hygiene Air Studies 12 years 10 months ago #2
You did it again. You successfully described everything wrong with North America.
First, there is the improperly installed or improperly maintained plumbing. There are Federal, State and Municipal laws governing this, however, when your Congressman is (wink and a nod) going to lunch with the developer, you will be hard-pressed to even get a response from the City Inspector.
Second, if the building manager/facility manager/owner/employer had true concern for their population/employees they would invite OSHA in to do the testing. I worked for ONE employer in my entire history that did that. They come in for free, give you a grace period to correct deficiencies then re-inspect (did I mention for free?). Now, when there is a medical facility in play, you never want the government involved because then it becomes a MATTER OF PUBLIC RECORD and just any idiot or advocate who wants to protect himself or a loved one can get it by Freedom of Information request (FOIA request) and if there is a serious problem it could even get into the NEWSPAPERS - and we wouldn't want that.
I have no experience with the 'sniffers', but all workplace chemicals should be examined for High Level exposures and Time Weighted Averages. This Hygienist business just seems like a Flim Flam.
One of the world's largest safety product manufacturers just told me that the carbon lots that they get sometimes have a distinct organic chemical odor that results from the treatment of the carbon. Up to that point I didn't know that carbon was not just carbon. Depending on what you are filtering for (personal safety equipment) there may be potassium permanganate and other filtration media, the carbon can be doped with metal halides in order to pick out small things like formaldehyde...after a while your eyes glaze over...
...some carbons are not virgin, but are reprocessed by a steam treatment....
Someone asked me recently if the carbon might stink because it might be coming from China - and that's when I really got concerned...
Regarding reacting to PPB instead of PPM: I worked in a factory where I could tell the supervisor we needed to evacuate BEFORE the sensors alarmed. They called me The Canary. No one could understand how I knew there was even a problem when they couldn't even smell it at the alarm point.
Someday, I would like to publish and make some money off of what I have learned, but the Internet will soon go the way of the Tower of Babel and the Great Library at Alexandria because knowledge has to be suppressed so I will offer this insight as a gift for peace of mind and rebuttal to the idiots that claim we are all NUTS:
There is an UNDENIABLE MATHEMATICAL relationship called the LD-50. This is the Lethal Dose of any substance that will cause death in 50% of a given population. This is a typical Bell Curve. The 'normal' responders fall in the major hump under the Bell Curve. That means that there will be individuals who will require MORE POISON before they sense, or succumb to effects. This is another 25%. THE LAST 25% ARE THE ONES WHO TAKE VERY LITTLE FOR IT TO BE A LETHAL DOSE!
This proves mathematically, with the fundamental undisputed science that Toxicology was based on, that you CAN be sensitive to LOW LEVELS of toxins.
Anyone who scoffs at you is too ignorant to do simple math and I always encourage people to stand up for themselves and rub the insolent offenders' noses in it.
Thanks again for a wonderful, informative post, Bolam.
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Re:Deceptive Practice/Industrial Hygiene Air Studies 12 years 9 months ago #3
Here's the detail on that electronic sniffer... The site: www.pnl.gov/main/publications/external/t...s/PNNL-14967Rev1.pdf
What it says: Performance Evaluation of Industrial Hygiene Air Monitoring ... On page 56, Section 4.4 of the document \"General Observations 4.4.1, Use of MIRAN Chemical Filters\", they state:
4.4 General Observations
4.4.1 Use of MIRAN Chemical Filters
\"It was discovered when zeroing the MIRAN instruments that the supplied chemical filters did not obtain the same results as found when zeroing the instrument on pure Aadco air. Even though the instrument displayed an \"OK\" when zeroed using the chemical filter, its readings went negative when it was then subjected to zero air from the Aadco system in preparation for a gas trial run. The trace was driven (continued on page 57) negative by approximately 15%. This was evidence that the chemical filters, which were protected from the ambient air in a Ziplok bag, as delivered to PNNL with the newly acquired instruments, were not able to obtain a true zero baseline. Except for several early runs, the chemical filter was not used during the testing. It is interesting that when the negative readings, recorded for the tests, were used as though they were good data points, the overall test results were considered satisfactory. The negative readings were zeroed out by adding the same positive number to all data points for the run\".
What I find most interesting about this is where they state: \"Except for several early runs, the chemical filter was not used during the testing\".
They got such screwy results with the callibration filter, they didn't even publish them in their findings, yet this is how the divice is used in the field!
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