Portable air purifiers are popular consumer items, especially in areas with poor air quality. Unfortunately, most users of these air purifiers have minimal understanding of the factors affecting their efficiency in typical indoor settings. Emission of the air pollutant ozone (O3) by certain air purifiers is of particular concern. In an effort to better educate the public, we created a laboratory protocol aimed at characterizing the performance of air purifiers designed for rooms, refrigerators, cars, and personal use. The laboratory protocol relies on standard aerosol particle counting techniques to measure the clean air delivery rate (CADR) and UV photometry to quantify the ozone emission rate for air purifiers. The students analyze their measurements and discuss the implications for indoor air quality and ozone chemistry. The laboratory is suitable for students with a wide range of education and laboratory experience.
Supplement
Instructions for the students; Notes for the instructor; Prelab and post lab questions
Experiments, laboratory exercises, lecture demonstrations, and other descriptions of the use of chemicals, apparatus, instruments, computers, and computer interfaces are presented in the Journal of Chemical Education as illustrative of new or improved ideas or concepts in chemistry instruction and are directed at qualified teachers. Although every effort is made to assure and encourage safe practices and safe use of chemicals, the Journal of Chemical Education cannot assume responsibility for uses made of its published materials. Many chemicals are hazardous. Precautions for the safe use of hazardous chemicals and directions for their proper disposal are described in the Material Safety Data Sheets and on the labels. We strongly urge all those planning to use materials from our pages to make choices and to develop procedures for laboratory and classroom safety in accordance with local needs and situations.
The "Chemistry Teacher Connection" (CTC) is especially for high school chemistry teachers. For only $40/year, it offers an online-only subscription to CLIC along with membership in the Division of Chemical Education, normally $65/year. CTC subscribers receive access to all articles and supplements from 1996 through the current issue.
Through special arrangement with the ACS, JCE High School CLIC is now able to provide subscribers with online access to Chemical & Engineering News articles that have been selected specifically for secondary science instructors and their students.
Occasionally, collections of JCE back issues become available for donation to individual teachers, schools, or libraries. JCE matches collections with interested recipients. Recipients pay shipping costs or pick up the collection.
Caution! 
Always in the