1. Scope

1.1 The test method challenges portable air and induct cleaners to remove target chemicals and a challenge aerosol. This test method evaluates the extent that portable air and induct cleaners produce a limited set of byproducts. Byproducts analyzed in this method include formaldehyde, ozone, nitrous oxides (NOx), ions, and ultrafine particles.
This test method is not pertinent to biological aerosol inactivation of air cleaning devices nor any biological induced chemistry.
1.2 The analysis of potential non-target chemicals produced by air cleaning technologies is covered in ASTM DXXXX (Standard Guide for Non-Targeted Chemical Analysis of Air Cleaning Technologies).
1.4 The method involves either 1) placing a single portable air cleaner in a walk-in chamber or 2) placing an induct air cleaner in a duct without heating or cooling equipment attached to a chamber. The non-reactive chamber (25 to 125 m3) operates at 25 °C +/- 1 °C and 50 % +/- 5 % relative humidity. A mixing fan is present in the chamber. Air is not recirculated through heating and cooling systems during portable air cleaning operation. Air is recirculated for induct systems at a rate of X h-1. Standardized challenge chemicals and aerosols are introduced to the chamber. Target challenge chemicals include formaldehyde, isoprene, xylene, D5 siloxane, and propylene glycol. Standardized aerosol chemicals consist of potassium chloride and have a size distribution of E.
1.5 Four experiments are done for each air cleaner. Target chemicals are spiked into the chamber and concentrations are monitored over time, first with the air cleaner off (control test) and then the method is repeated with the air cleaner on. Next aerosols are spiked into the chamber and concentrations are monitored over time, first with the air cleaner off and then the method is repeated with the portable air cleaner on. The air cleaners ability to remove the target chemicals and aerosols, along with byproduct production is assessed by comparing the tests.
1.6 Clean air delivery rates (CADR) are calculated for target chemicals and challenge aerosols. Formaldehyde, ozone, nitrous oxides, ions and ultrafine particle production are also determined.
1.7 Target chemical analysis is performed via either time-averaged analysis or real-time instrumentation. Aerosol analysis is performed using a particle counter with the capability to detect particles with a diameter of 12 nanometers or lower.
1.8 This method does not determine all potential byproducts produced by air cleaning devices. The method does not address any health effects of any byproduct production.
1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Keywords

Chemistry; Air Cleaners; portable; induct

Rationale

The pandemic has resulted in heightened awareness of the need to clean indoor air. This resulted in a large number of new and revised air cleaning products being brought to market. While there exist standards that can evaluate the performance of large particle removal of these technologies, there are no standards that evaluate the chemical and ultrafine particle removal. In addition, there are no standards that evaluate the potential byproduct creation by various air cleaning technologies. This proposed standard is an attempt to level the playing field so the chemical performance (removal and byproduct creation) of all air cleaning technologies can be evaluated using a consistent method.

The title and scope are in draft form and are under development within this ASTM Committee.