Just so you'll know, the National Institute for Occupational Safety and Health maintains a "Certified Equipment List" for respiratory protection. You can check it here:
http://www.cdc.gov/niosh/npptl/topic...L/default.html
http://www2a.cdc.gov/drds/cel/cel_form_code.asp
If a respirator is not certified by NIOSH, you cannot assume that you'll be fully protected against toxic substances. There is a list of manufacturers on this site, and Moldex is one of them (it is on the Certified Equipment List).
I could not find the Respro Sportsta respirator on that list. I note that it is advertised as meeting the European Standard EN149FFP1(S) for solid aerosol particles. When I try to search the standard, all I get is advertisements. So I went to the EN Standards Index:
http://en-standards.standardsdirect.org/
I could not see that one listed. So I went to EN148 to take a look. I got into an index which should have the EN149 standards listed, and do not find this one:
http://en-standards.standardsdirect....4_list_34.html
This doesn't mean it's not there, only that I cannot find it. I would therefore be rather cautious about this respirator.
Since I posted the above about diesel not being filtered by N95 respirators, I attended the American Industrial Hygiene Conference and Exposition (AIHce) is Philadelphia this spring. I attended a Roundtable discussion by leading experts in nanoparticles, and diesel exhaust did come up. Apparently, there are now some studies which show that nanoparticles are filtered out by the N-99 particle respirators. Here is the home page for NIOSH Safety and Health Topic: Nanotechnology:
http://www2a.cdc.gov/niosh-nil/index.asp
NIOSH has yet to really address the issue of personal protective equipment (PPE, or respirators) for nanoparticles. But I asked this question directly of one of the NIOSH speakers, who happened to be a bicyclist, "Should we be wearing a respirator when bicycling in traffic?" He answered that he did not, and was relying upon the clearing mechanism of his lungs to get rid of the particles.
But this was before the recent
The New England Journal of Medicine article by N.L. Mills and Others titled "Ischemic and Thrombotic Effects of Dilute Diesel-Exhaust Inhalation in Men with Coronary Heart Disease." There is an editorial along with that, titled "Air Pollution, Exercise, and Cardiovascular Risk," by M.A. Mittleman. Here are a few sentences from that editorial:
There is mounting evidence that exposure to higher levels of air pollution is associated with adverse cardiovascular consequences. A recent scientific statement from the American Heart Association concluded that transient changes in air pollution are associated with a short-term increased risk of cardioascular disoeas and death. There is also convincing evidence for an association between air pollution and myocardial ischemia and infarction, ventricular arrhythmia heart failure exacerbation, ventricular arrhythmia, heart failure exacerbation and stroke...
In this issue of the
Journal, Mills and colleagues report the results of a double-blind, randomized, crossover study of 20 men with a history of myocardial infarctino exposed to either dilute diesel exhaust -- at a level similar to what might be routinely experienced when driving in traffic -- or filtered air. During each exposure period, subjects exercised on a bicycle ergometer to a target of 5 to 7 metabolic equivalents for two 15-minute periods separated by 15-minute rest periods. The researches found that although the heart-rate response to exercise was not different across exposure periods, myocardial ischemia, which was detected in all patients, was associated with significantly greater ST-segment depression and a greater ischemic burden during exposure to diesel exhaust than during exposure to filtered air...
...The evidence from Mills and colleagues suggests that the risk of having an acute cardiovascular event triggered by vigorous exertion may be heightened with exposure to high levels of air pollution. Considering the unequivocal benefit of habitual exercise, including its established role in decreasing the risk that isolated episodes of exertion may trigger the onset of an acute cardiovascular event, the risk-benefit ratio may be optimized if people exercise away from traffic when possible. N ENGL J MED 357;11,
www.NEJM.org, September 13, 2007, pgs 1147-1148
To me, it means that I have dusted off my respirator, and it is now on my bike. My bike route to and from work normally carries me on bike paths, back roads, and perpendicular to major traffic, thereby decreasing the potential for diesel exposure. But yesterday, when a dump truck passed and laid down a virtual curtain of diesel exhaust, the respirator came out and for the last 3/4 of a mile, I wore it.
I'm using a North 7700-30L half-face respirator (large) with HEPA filters (DOP12H4, colored purple). This type of respirator has an advantage over the ones above, in that the half-face respirator can be washed after each use, if needed. The cartridges can also be replaced if they become clogged (they are more efficient with time for particles). This does not filter vapors or gases, so CO and benzene will go right through. But the diesel particles will be filtered. I am not advocating North's respirators, as Wilson, 3M, and others make equally effective respirators. I am advocating this type of respirator. Here is what it looks like:
http://www.labsafety.com/store/Safet...oredirect=true
(See the EZ-Facts sheets on the side of this page; the HEPA filter is the 41590 P100 Filter shown in the link "View respirator cartridge, filter and accessory charts.)
By the way, LabSafety is a good source for this kind of equipment. There are also local safety supply houses which can give good advise and have good equipment. I also use Sanderson Safety and Supply in Portland, Oregon if your are around here:
http://www.sandersonsafety.com/
In the Seattle are, there is Safety & Supply Co.:
http://www.safetyandsupply.com/home.asp
There are many, many more throughout the world, but go to a reputable safety supply house, and make sure of the certification of the respirator you pick up.
John