Thanks for producing this video; this is helpful. The safety concerns raised by the recent FDA consumer advisory focus on injuries to consumers ingesting food prepared with liquid nitrogen at the point of sale. The video addresses these issues to some degree, but I think some questions remain. The video advises us to make sure the nitrogen has fully sublimated before serving it. Are there more definitive criteria we can use to help determine whether the nitrogen has fully sublimated? Visible vapor is not necessarily a good indicator, because that depends on moisture content of the air. Wait time prior to serving? This will depend on the volume of the food prepared and storage conditions.

At UNH, our Chemistry club students wanted to serve liquid nitrogen ice cream at a public event just days after the FDA press release. The public had just been warned to avoid consuming food prepared with liquid nitrogen, so this raises the bar for the assessment of hazards. How do we we assure the consumer there are negligible risks, other than by saying, it's probably fine or, we've never had an issue before?

Thanks,

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