PM 2.5 Indoors

By Diana L. Larson posted 08-27-2020 03:40 PM


Is anyone aware of any guidance or standards specific to particulate levels (PM 2.5) for assessing indoor air quality? In California, we are experiencing very poor ambient air quality due to wildfires and many of our building occupants are concerned about particulate levels inside the building from the smoke. Ventilation systems at our site vary by building and some will vary by lab space, each can draw in differing amounts of fresh air. We have received requests from building occupants to evaluate indoor air quality for particulates. So aside from comparing inside with outside air readings using the same instrument (such as a Dust Track or an EVM), is anyone familiar with any guidelines or criteria that can be used for evaluating results of direct reading instruments for PM 2.5?  

Dian Larson, PhD, CIH, CSP
Industrial Hygiene Group Leader
Lawrence Livermore National Laboratory


01-04-2021 09:35 AM

AIHA Publication "The IAQ Investigator's Guide" has listed standards/guidelines for both PM 10 and PM 2.5 (pages 89 and 90 respectively in the 3rd edition).

PM 2.5
35 ug/m3 (standard) - EPA - 24 hour average outdoor
12 ug/m3 (standard) - EPA - annual average outdoor
12 ug/m3 (standard) - CA - annual average outdoor
levels commonly found indoors 1 to 25 ug/m3

09-16-2020 07:15 PM

What Adjustment Factor is reasonable for applying to Dusttrak DRX 8534 for woodfire smoke.  Ive read a few of the recent articles and see different values. TSI indicated only Diesel has been provided with a AF (0.37 if i recall correctly).  Without side by side gravimetric data to calculate an AF for wood smoke with the dusttrak measurements,  wondering if anyone is using 0.47 or similar?