I've been struggling with the same issue, and various sources came up with these resources: a statement from one manufacturer basically saying it's fine, no further mitigations needed https://looksolutionsusa.com/faq-for-fog-haze-and-covid-19/ A report all but saying 'haze is the new vaccine' https://www.asepo.org/FogSafety and a rather more cautious report from some safety consultants which essentially says 'it's up to you, pal, there's no obvious risk, but there isn't very much to tick the box proving there isn't very much risk...' https://www.firstoption.group/what-s-new/news-posts/fog--haze-machines-and-covid Based on the above, we've decided to go ahead and use it.