From: Allen Jones <arjones999**At_Symbol_Here**GMAIL.COM>
Subject: Re: [DCHAS-L] Runaway Hot Plates
Date: Wed, 22 Apr 2015 09:24:46 -0400
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: CANRqTd-+NsZH_1fCvtrDCqWZVRViOfZrQ9Xoti1BJCHVrnqTpg**At_Symbol_Here**mail.gmail.com
In-Reply-To <2c05874dfa89441caff680c445b46b17**At_Symbol_Here**EXCHCS34.ornl.gov>


We have had an occasional hot plate over heat. To reduce this and other risks we implemented three layers of protection for work in laboratory hoods with good succes.

1. Outlets on the face of the hoods are on timers that are only powered during the week day operating hours.
2. All systems are unplugged at the end of the day by the operator(s), hotplates, immersion heaters (with over temp fuses), pumps, power supplies, etc.
3. Lab shut down sign out process for the last two persons in the lab.

We also have unattended forms for overnight testing.

Best regards,
Allen Jones

On Tue, Apr 21, 2015 at 8:20 PM, Pickel, Joseph M. <pickeljm**At_Symbol_Here**ornl.gov> wrote:

In the past year, we have had a series of issues with "runaway" hot plates. In the first instance, a hot plate in the off position began heating in an unoccupied laboratory resulting in a hood fire. Since then we've observed another hot plate that was heating while in the off position as well as a hot plate that heated uncontrollably while on a low setting. The hot plates that were in use were all relatively new and issues look to be caused by failed circuit boards.

I presented some of the lessons that we learned from these events at the recent ACS National Meeting and was surprised with how many researchers stopped by my poster to indicate that they have observed the same issues. Descriptions of some of these events and additional details can be found at the following links:

https://opexshare.doe.gov/lesson.cfm/2014/12/11/4670/Electronic-StirrerHot-Plate-Malfunction-Inside-Glove-Box

http://www.research.northwestern.edu/ors/forms/CSHEMA%20Hotplate%20Poster%202014.pdf

https://www.drs.illinois.edu/News/Warning-about-malfunctioning-hotplates

We're advising our folks to keep hotplates unplugged when not in use and use stirring-only hotplates where possible. In addition, some groups are considering getting rid of their existing hotplates and buying new models, but I fear that these may have the same potential issues. The possibility of installing an on/off switch on the cord has also been discussed, and while this will prevent hot plates from heating while in the off position, it might not help the issue of hot plates running away (uncontrolled) when the hot plate is intentionally turned on.

I'd like to poll the group- has anyone else had similar issues, and more importantly... what kind of solutions have you identified?

Thanks,

Joe Pickel


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