From: Jeffrey Lewin <jclewin**At_Symbol_Here**MTU.EDU>
Subject: Re: [DCHAS-L] Natural Gas in Science Buildings
Date: Wed, 17 Sep 2014 16:31:40 -0400
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: CAEwQnqjdwCdUBdp9jS+L0P9nNHWQjaMJoij7QsRW7YJbFF+BPA**At_Symbol_Here**

My perspective is from biological sciences, including biochemistry.


The building (primarily research), with three class rooms including those for microbiology and biochemistry, I'm located in was built ca 1999. It includes individual manual master gas shut offs in the room usually, but not always, near the door. One must be vigilant that these are not obstructed since they often are put randomly on a wall where it would be logical to put furniture, file cabinets or equipment. The building has a building master shutoff at the gas meter, essentially an electromagnet that holds a counter weight. When the power goes out or the fire alarm goes off the magnet shuts off, dropping the weight and closing the valve. It has to be manually reset.

Our most recent building, opened two years ago, has moved the room master shutoffs to the hallway. I like this much better since they are less likely to be blocked. And, should someone open a lab door to smell gas they don't have to fumble around in the dark, or risk a spark turning on the lights, to find the shut off.


By far the most common use for flames in biology is sterilization. General heating is done with hot plates, ovens, autoclaves or other heating devices. Occasionally someone will use a flame to polish the ends of glass stirring rods, pulling the tips of Pasteur pipettes for finer tips, etc. Most use flame sterilization because it is, "the way its always been done," the equipment is cheaper up front, not wanting to use disposables and often it is faster than other methods. Bacterial loop sterilization is often done in flames but you can also buy table top incinerators that work pretty effectively. We've started to push these in in our instructional labs since they are generally safer (no open flames) and, while unlikely, you don't risk bacteria boiling and popping off the loop before it actually gets killed/sterilized. Another alternative is to purchase pre-sterilized disposable loops. Microbiology labs also spend a lot of time making slides. There are two steps that require heat - heat fixing and slide drying. We've purchased trays that go over the end of the incinerators and (actually just this week) finally got them adjusted to dry slides quickly. However, they are still very slow for heat fixing hence this step is still often done over an open flame. There are other sterilization techniques, such as flaming the end of test tubes and flasks before and after transferring bacterial inoculated liquids, that don't have very good alternatives.

Problems with flames, a couple of specific examples. Aside from the chance of catching one on fire from an open flame I've seen several issues that I try to use at various training sessions:

The melted HEPA filter. Biological Safety Cabinets (BSC's) are specialized hoods for working with bacterial cultures. Because they also take in sterile air they are often used simply as clean hoods for plant and animal tissue culture, pouring sterile plates and transferring bacteria. We have these certified every year. During one certification the technician couldn't get the flow stabilized. It turned out that the flow sensor had been melted, most likely from an open flame. He indicated that he had seen HEPA filters (big bucks to replace) melted by open flames. So I try to insist on incinerators in BSC's; BSC's with gas jets inside the hood are NOT connected.

The exploding alcohol lamp. This personally happened to me. I was teaching a lab as a graduate student where we were using alcohol lamps for sterilizing loops. I went to move the lamp from one table to another, absentmindedly forgetting to put it out. As I carried the lamp, the wick fell into the alcohol and exploded in my hand.. Fortunately I did not get hurt nor did my clothes catch on fire. However the alcohol fire slowly worked its way under a lab bench prompting me to finally put it out with a fire extinguisher. I discovered then how much of a mess a fire extinguisher makes.

Fire and bulk alcohol. This is pretty recent and again something I witnessed. A graduate student was sterilizing a septum prior to extracting a sample from the large sample bottle. She was doing this in a fume hood (I never figured out why). Squirt some ethanol on septum, let it sit for a minute and burn any residual ethanol off. The problems? The squirt bottle being used continued to drip ethanol yet wasn't removed from the hood. And, what was worst, there was a carboy with 2 gallons of Ethanol sitting in the hood as well. We had several discussions with lab users about proper storage and hazard awareness.


On Tue, Sep 16, 2014 at 5:34 PM, David Roberts <droberts**At_Symbol_Here**> wrote:
After reading these comments, these thoughts came to mind.

In all honesty, we rarely use natural gas in our gen chem labs. We have 1 lab where we look at flame tests - but that's it. It's not something that is used often. Our organic class occasionally runs a grinard reaction, and so it is used there for an experiment or two, but again, not often.

For instruments requiring continuous gas, of which only our AA comes to mind, we of course have tanks of acetylene and compressed air. So we are not using methane for any of our instrument fuels at the moment.

But, since starting our biochemistry major, we have a lot of use in that area in terms of sterile manipulation of things. This is where my hood comment came in to play, as you don't want to do sterile things in a chemistry fume hood as it=E2=80™s way too hard to keep plates sterile. The biochem majors use the gas constantly, mostly for flaming loops for inoculations or just for sterile pouring of solutions from one container to another. Very common.

One way I can sort of monitor gas usage is due to the fact that all of our rooms have electronic solenoids that trip in the event of a power outage. It storms a lot in Indiana, and so our rooms are often without gas. One needs a key to reset the safety, and I=E2=80™m the key master, meaning they don't get reset without my knowledge. Most of our rooms are off all the time, so overall use is very low.

You can do a lot with portable propane tanks (even Mapp gas is hotter). I find if I need to manipulate glass, I use Mapp gas or something similar, as it just works better for what I need. We have a few propane torches around, that we store properly, and use on occasion.

Our students would prefer to use hot plates for most things that require heating of solutions in a beaker. It's just easier and more stable, so they don't even think of using a burner for that. Hot plates aren't cheap though ;)

Good luck with this.


On Sep 16, 2014, at 2:22 PM, Kohler, Christopher E <cekohler**At_Symbol_Here**IU.EDU> wrote:

Thank you all. Your comments are, as always, very helpful.
While reading them I have come up with a theory. See if this has any merit and feel free to send comments (even if you think it's crazy!) J
Thinking back to my early days in chemistry I remembered that benches had plumbed natural gas so they could provide a "continuous" supply of gas. That "continuous" supply would be the only advantage over a source of heat say from a propane torch or an alcohol lamp.
These temporary devices can be used for sealing an ampule or bending an occasional piece of glass or even sterilizing an inoculating loop.
Then I asked myself why was there a need for a "continuous" gas supply? Other than an instrument flame, or bending or polishing glass it was used so we could heat or boil chemical solutions on the lab bench (before we students had instructional fume hoods of course).
Certainly, heating solutions today would be performed in fume hoods so the need for a "continuous" supply of gas at the benches diminished.
Today, bench installations with these gas taps now should probably be restricted to non-chemical use and monitored, otherwise the temptation still exists to put a beaker on a Bunsen burner and perform operations that should really be performed in a fume hood.
Make sense? Your thoughts?
Christopher E. Kohler
Laboratory Safety Manager
University Environmental Health and Safety
Indiana University
1514 E Third Street
Bloomington, IN 47405

Jeff Lewin
Departmental Laboratory Supervisor
Biological Sciences
Michigan Technological University

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