There are some options for doing fit tests with cheaper equipment. Here's one that uses a humidifier and essential oil diffuser and compares them with the offic

There are some options for doing fit tests with cheaper equipment. Here's one that uses a humidifier and essential oil diffuser and compares them with the official testing equipment: https://www.cambridge.org/core/journals/disaster-medicine-and-public-health-preparedness/article/performing-qualitative-mask-fit-testing-without-a-commercial-kit-fit-testing-which-can-be-performed-at-home-and-at-work/41EDE04D0885104F2ECBF5725047D7C8 https://www.cambridge.org/core/journals/disaster-medicine-an...