[labnetwork] Gas cabinet for F2 premix for excimer lasers?

[Morrison, Richard H., Jr.]

Hi All,

At Draper we have two Excimer lasers that use the F2 premix gas and both machines have the premix in a gas cabinet. Yes it cost more upfront but better to be safe than sorry.

Rick


Richard H. Morrison
Principal Member of the Technical Staff
Draper
555 Technology Square
Cambridge, MA
02139-3573

Work  617-258-3420
Cell  508-930-3461
www.draper.com<http://www.draper.com>



From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Sandrine Martin
Sent: Friday, March 03, 2017 2:29 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Gas cabinet for F2 premix for excimer lasers?

Hello,

There are a few individual labs here at the University of Michigan that have excimer lasers and use F2 premix gases with 0.1 or 0.2% F2. So far, these gases have been installed in gas cabinets. We are now involved in a new installation and are getting some push back about the need for a gas cabinet.

The argument is made using the Compressed Gas Assoc Pamphlet P-20 Standard for Classification of Toxic Gas Mixtures (2009) that apparently states that, if the LC50 value is over 5,000ppm, the gas mixture is not considered toxic.
Pure F2 is listed with a LC50 (rat, 1h) at 185ppm.
At 0.2% F2, the calculated LC50 is then 92,500ppm, well above the 5,000ppm threshold and the premix is no longer considered a toxic gas. (it also has an NFPA rating of  "1" in health on the MSDS)

Since the mixture is not toxic and the F2 concentration is <1%, EH&S concludes that a gas cabinet is not required.

However, considering that the F2 PEL is 0.1ppm and IDLH 25ppm, it still seems that a gas cabinet would be the safest option and the best solution.

Has anybody gone through similar discussions?
If you have a lab with a fluorine premix gas, is it in a gas cabinet? If not, what type of space is it in, and what kind of ventilation and gas detection are in place?

Thanks
Sandrine


--

Sandrine Martin, Ph.D.

University of Michigan

LNF Managing Director

1246D EECS, 1301 Beal Ave

Ann Arbor, MI 48109

Cell 734-277-2365

Fax 734-647-1781

www.LNF.umich.edu<http://www.lnf.umich.edu/>

@LurieNanofab

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