Talk:Microparticle performance rating

Useful information

This page was useful to me. The info. is hard to find. Needs supplementation, cross-links, cites, etc., but the testing info is not so easy to find.

It appears that MPR measures filtration of ultrafine particles, which are smaller than 1 micrometer. MERV measures PM10 and PM2.5. MPR seems to include a focus on the much smaller particles less than PM1 and down to PM0.3:

The indoor pollutant that scientists believe may be most harmful to human health is particles, including fine particles, which are less than 2.5 micrometers in diameter, and ultrafine particles, which are smaller than 1 micrometer. They are produced by both gas and electric burners and by cooking. They are potentially very harmful because they can enter the lungs and, for the smaller particles, enter the bloodstream or other tissues.

http://newscenter.lbl.gov/2013/07/23/kitchens-can-produce-hazardous-levels-of-indoor-pollutants/ Berkley Labs (lbl.gov)

The difference has consequences because the smallest nanoparticles are most able to penetrate into the alveoli of the lungs, make their way into the bloodstream, and slip through the blood-brain barrier.

MPR is 3M only, a one-company "standard"; this needs more emphasis in this article.

By not emphasizing that "MPR" is an invention of 3M and is used only by 3M - even though an internationally agreed-upon standard for measuring the exact same thing exists- the article is misleading readers through an act of omission.

The article falsely claims that MERV measures large particles while MPR measures small (.03). This is just false. MERV measures ALL particle sizes including small (.03). In fact what MPR measures is a proper subset of what MERV measures. The article gives the impression that they measure two different thing- large (MERV) and small (MPR).

Although 3M is a multi-billion dollar company, they have never published the MERV values of their filters. Instead, they created their own rating system. This is significant because MERV is the internationally recognized measure of filtration and the industry standard for filtration where such filtration is regulated by law. Since MERV measures exactly what MPR measures, the question is- why does 3M not publish their MERV ratings?

MERV ratings specify what percentage of what size particles are passed by the filter. MPR is a non-specific, non-quantitative "relative goodness" rating which does not specify what percentage of what size particles the filter passes.

I only go into this level of detail so readers of this talk page will be sufficiently grounded in the context of filter ratings to understand what the issue with this Wikipedia entry is. — Preceding unsigned comment added by 213.152.162.89 (talk) 03:05, 26 June 2016 (UTC)