I believe the cost issue was related to the quantity of food grade liquid N2 that would have to be purchased which was far more than needed.

And there's nothing wrong with using liquid nitrogen for preserving food. There's just something wrong with preparing food in a demonstration lab environment with chemistry students who are untrained in proper hygiene for commercial food preparation. It's hokey and the wrong lesson.

There are so many things that can go wrong here.

We make theatrical fog with both dry ice and liquid N2, and where you see that mist (which is being incorrectly referred to in this discussion as "fume"), the level of oxygen is quite low. We have had people lying on the stage pretending to be dead to go into seizure due to oxygen deprivation. So when they talk about good ventilation with this project, they mean GOOD VENTILATION.

Monona Rossol, M.S., M.F.A., Industrial Hygienist

President: Arts, Crafts & Theater Safety, Inc.

Safety Officer: Local USA829, IATSE

181 Thompson St.., #23

New York, NY 10012 212-777-0062

actsnyc**At_Symbol_Here**cs.com www.artscraftstheatersafety.org

-----Original Message-----
From: Margaret Rakas <mrakas**At_Symbol_Here**SMITH.EDU>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>

Sent: Wed, Sep 26, 2018 1:45 pm
Subject: Re: [DCHAS-L] Restaurant use of liquid nitrogen for ice cream?

Regarding "food grade" liquid nitrogen...

We called our supplier. I can't speak for anyone else's but

1) there is no extra cost for 'food grade'

2) we were informed by our supplier "The Liquid Nitrogen [we sell] for food grade is the same stuff, it just comes with a Lot # and a CoA so you know that it passed muster."

LN2 has been used for quite some time for food preservation; here is a link to a book chapter noting that it has been used in Europe since the 1960's and the book itself was published in 1991...

The use of LN2 in food freezing

My personal experience/opinion, definitely not business or legal advice..

Margaret

On Wed, Sep 26, 2018 at 11:15 AM Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**lists.princeton.edu> wrote:

"Its probably fine? We've never had an issue before?" Where have I heard those statements before? Why do you want to encourage students to make the same waffling statements you hear from businesses trying to justify their lousy products?

We are safety people. We should be following all of the applicable laws and safety regulations. In a previous post there was acknowledgement that only food grade liquid nitrogen was approved for this purpose, but, hey, it's expensive so they just let them make it with lab stuff.

What other food safety laws might not be being met with your equipment, training, location of service, or other issues? You should be talking to local health authorities who enforce the food safety regulations about how good and idea this is and get some kind of more official permission to make and serve ice cream.

Food doesn't belong in the lab. And lab chemicals don't belong in food. It isn't just the risk, it's the wrong lesson you are teaching.

It reminds me of the pizza party the teacher and students invited me to in a College in Arizona after I did an OSHA training. I demurred when I learned that the pizzas were made in ceramic kilns.

Monona Rossol, M.S., M.F.A., Industrial Hygienist

President: Arts, Crafts & Theater Safety, Inc.

Safety Officer: Local USA829, IATSE

181 Thompson St., #23

New York, NY 10012 212-777-0062

actsnyc**At_Symbol_Here**cs.com www.artscraftstheatersafety.org

-----Original Message-----
From: Glode, Andy <andy.glode**At_Symbol_Here**UNH.EDU>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Wed, Sep 26, 2018 8:34 am
Subject: Re: [DCHAS-L] Restaurant use of liquid nitrogen for ice cream?

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,

Andy Glode

Laboratory Safety Manager

Office of Environmental Health and Safety

University of New Hampshire

603-862-5038

https://www.unh.edu/research/environmental-health-and-safety

---

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> on behalf of Jyllian Kemsley <jyllian.kemsley**At_Symbol_Here**GMAIL.COM>
Sent: Tuesday, September 25, 2018 5:12 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Restaurant use of liquid nitrogen for ice cream?

Caution - External Email

---

Hi everyone,

Following up on my previous post about using liquid nitrogen to make ice cream: Here's the final video!

https://cen.acs.org/content/cen/articles/96/i39/Making-liquid-nitrogen-ice-cream.html

Thank you very much to everyone who contributed to producing this, privately and through the list.

Jyllian

Jyllian Kemsley, Ph.D.

Executive Editor, policy and safety

C&EN | Chemistry news from around the world

M: (+1) 925-519-6681 | Skype: jyllian.kemsley

Twitter: **At_Symbol_Here**jkemsley

Want to be in the know? Sign up for C&EN's weekly newsletter: cenm.ag/newsletter

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--

Margaret A. Rakas, Ph.D.
Manager, Inventory & Regulatory Affairs
Clark Science Center
413-585-3877 (p)

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