DCHAS-L Archives, Oct 09 2018 - Re: [DCHAS-L] Laboratory Benchtops

Microbiology can be one of the more challenging ones, especially since the alternatives usually have a cost associated with them.

We recommend infrared loop sterilizers for loops and bead sterilizers for other tools. Alternately, you can use disposable items which have an obvious ongoing cost (as well a perception of being not very sustainable). Another alternative is to heat sterilize multiple tools (such as in an autoclave) in advance of the procedure. I'm aware one challenge is heat fixing slides; some manufacturers of loop sterilizers make a small tray that attaches to the end of the unit. I've not used them myself, but I'm told they don't work as effectively as an open flame, although it may be impatience in that it takes a little longer or the trays may not be installed correctly.

We _strongly_ discourage open flames in Biological Safety Cabinets (BSCs), and we have a melted flow sensor to show as an example. Our service techs tell us they have seen HEPA filters melted by Bunsen burners being used in BSCs.

If after evaluating all the alternatives and it turns out flame sterilization is the best option I've started developing the following guidelines - I appreciate any comments or suggestions.

If an open flame must be used in the laboratory, the following controls must be incorporated into the Standard Operating Procedure (SOP):

- A class ABC fire extinguisher must be available.

- Anyone working with an open flame must be taught the appropriate response of "Stop, Drop, and Roll" in the event their clothing or hair catches on fire.

- Flame-resistant (FR) lab coats and appropriate eye protection are required when working with open flames. Workers are also encouraged to wear non-synthetic clothing under the FR lab coat.

- Open flames are not to be used under cabinets or shelving.

- Remove all combustible items from the work area; NFPA guidelines are minimum of 2 feet

- If flammable liquids are required for the procedure, use the smallest quantity possible; NFPA guidelines limit quantities to 50 ml or less and in a metal or glass vessel and shall have a tight-fitting lid that can slip on top when not in use or if the flammable liquid catches on fire.

- NFPA guidelines are to keep flammable liquids a minimum of 1 foot from the flame.

- Cap and remove any bulk flammable liquid containers from the work area.

- Extinguish the flame and wait several minutes before refilling any flammable liquid reserves.

- DO NOT REFILL liquid reserves when a flame is present.

All fires, even if extinguished, and all discharges of fire extinguishers must be reported to Public Safety and Police Services. An Incident Report must also be filed with Environmental Health and Safety (EHS).

Note that activities that use open flame for soldering, brazing, or welding, or that use open flame for glass blowing or glass manipulations require a hot work permit unless performed in a location pre-approved by EHS or Facilities Management for such work.

Jeff

On Tue, Oct 9, 2018 at 12:05 PM Pam <aubu**At_Symbol_Here**hotmail.com> wrote:

Jeffrey

Can you tell me what you are now using for sterilization? The person teaching microbiology told me that they could not obviate the use of Bunsen Burners

Thanks

Pamela Auburn, PhD
2041 Branard
Houston TX 77098

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> on behalf of Jeffrey Lewin <jclewin**At_Symbol_Here**MTU.EDU>
Sent: Monday, October 8, 2018 4:07 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Laboratory Benchtops

Two years ago, when I was on the academic side, I'd probably be asking the same question.

However, I think the first step is to go back to the engineering team to see what was specified. It is possible (likely) that they specified chemical resistant, but not heat resistant, lab benches, although I'd be very surprised if they didn't meet flammability codes. It would be too bad if they did, but likely to cut costs on the project.

I'd also note, that I discourage people from placing hot glassware on cold lab benches, even Pyrex or similar glassware since it increases the chance of it breaking.

And, an in an interesting twist on codes, the 2015 NFPA 45 Standard on Fire Protection for Laboratories Using Chemicals has the following statement:

"11.2.7 Open Flames

11.2.7.1 Laboratory operation using open flames shall be performed in accordance with the following requirements:

(1) Whenever possible, alternative methods to the use of open flames, such as heating mantles, hot plates, glass bead sterilizers, or infrared loop sterilizers shall be used."

It then goes on to give specifics to follow when using flames, including section 11.2.7.2 outlining "Biological operations using open flames and flammable liquids..."

Following a small fire in a lab last week (flame sterilization using flammable liquids), we've started a campaign to eliminate flames from the lab, when feasible.

Jeff

On Mon, Oct 8, 2018 at 9:10 AM Pam <aubu**At_Symbol_Here**hotmail.com> wrote:

All

The institution where I teach has just completed a new science building. This is my first semester working there. It was noted during our last lab that the benchtop material is not heat resistant. When hot beakers were placed on the surface it bubbles, burned and delaminated. My guess is that someone was trying to save money.

What I am trying to figure out is whether there are applicable safety and or fire codes. It seems reasonable to expect that benchtops in chemistry labs should be heat and fire resistant. Under normal operating conditions we are working with hot glassware and sometimes use Bunsen burners or other sources of flame.

Thank you for your help

Pamela Auburn, PhD
2041 Branard
Houston TX 77098

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--

Jeff Lewin
Chemical Safety Officer

Compliance, Integrity, and Safety

Environmental Health and Safety

Michigan Technological University

Houghton, MI 49931

O 906-487.3153

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