Jim Rosenthal ’70 is the CEO of Tex-Air Filters and the co-creator of the Corsi-Rosenthal Box – a low-cost, do-it-yourself air filter made from air filters and a box fan.
When he and his co-developer, Dr. Richard Corsi, Dean of Engineering at the University of California, Davis, introduced their concept during the height of the Covid-19 Pandemic, there were two things they were certain of: they wanted to help and they would keep the concept and design open-source.
“It was just the right thing to do,” says Rosenthal. “We didn’t want to make money on it. People could actually benefit by making one of these, put it in their house, and know that they were doing something to make their family safer. It was something that people could do instead of being helpless. This enabled people and empowered people to act. They could do something that made a difference.”
Rather than patent the design, Rosenthal and Corsi trademarked the name and used that name to start the Corsi-Rosenthal Foundation – a nonprofit that works to help provide clean air for underserved communities.
“We have an initiative in the organization called ‘Clean Air K12’ that focuses on schools, providing the materials necessary to make these boxes, instructions and lesson plans and everything that somebody would need to put it into a school,” says Rosenthal. “We have a grant process and we’ve been giving out grants for the last two years.”
The foundation was approached by 3M who offered to provide the filters which now accompany the foundation’s grants to schools.
Tested by the EPA, CDC, and other independent laboratories, over a quarter of a million Corsi-Rosenthal Boxes have been built since the first model was constructed in August of 2020. The tests continue to show the effectiveness of CR boxes in removing viruses and other airborne contaminants from indoor air – at a fraction of the cost of conventional HEPA air cleaners. For his invention, and the charitable work he did with it, CC granted Rosenthal an honorary degree at the 2024 Commencement Ceremony.
When the Los Angeles fires hit in January 2025, the Corsi-Rosenthal Foundation was inspired by one of its board members to get involved. A team spanning several states worked to have the supplies shipped to San Diego, CA where 1,150 kits were assembled and sent up to LA via a fleet of U-Haul trucks.
“We found places where they needed them and would be able to put them into immediate use,” says Rosenthal. “One of the key elements was getting the filters there quickly because, what happens when you have a wildfire, within the first 24 hours, every store is out of filters. The Foundation’s rapid response enabled users in LA to have cleaner air while the fires were still burning.”
While Rosenthal hopes there isn’t another disaster requiring such a rapid response and immediate need for his boxes anytime soon, he is confident in the good his organization is doing.
“The mission is to grow the Foundation,” he says. “To get as many people as possible to have good indoor air. It’s simple and it’s not expensive. My goal would be to have two of these boxes in every classroom in the United States. That would be wonderful.”
In the meantime, the next thing on his to-do list is leading a Half Block at CC. Rosenthal will be on campus in January 2026 teaching GS222 Breathe Easy: The Environmental Health and Science of Indoor Air, an air science course in alignment with CC’s focus on sustainability.
“We plan on doing some field trips to the universities that have laboratories on indoor air quality and then doing a lot of hands-on training to explain to students how air conditioning systems work, how filters work, and how the box works,” he says. “I have lots of particle counters and CO2 meters, so it’ll be a real hands-on learning experience.”
Rosenthal is looking forward to sharing his passion with the CC community and helping the next generation of students understand the science behind air quality.
“I do a lot of experiments, and I enjoy looking at particles and figuring out what works and what doesn’t work,” he says. “To me, it’s fun and I think I can make it fun for other people too.”