How about just using common sense.  Any carbon-based substance that burns will create toxic substances. Food and plant tissues contain sources of carbon, nitrogen and often some sulfur compounds.  Unless this muffle furnace also has a forced oxygen atmosphere, the results will include some carbon monoxide.  And even with an oxygen atmosphere there will be nitrogen oxides and sulfur oxides which all have TLVs and OSHA PELs.  If the early phases of the burn produce an odor, many more harmful chemicals are being emitted..

Remember, tobacco is just a plant.  And nicotine is not a carcinogen.  It is the burning leaf that kills.

Monona

 

-----Original Message-----
From: Stella Julia Sommer <0000071592c679d2-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Sun, May 12, 2019 11:18 am
Subject: Re: [DCHAS-L] Muffle Furnace Ventilation Requirements

Thank you Ms. Rossol & Mr. Palluzi,

I really appreciate your detailed responses & your help!

I know, a dedicated powered exhaust duct that vents to the outside would be the best solution.

However, it might take a lot of convincing to explain this to people who do not have a background in science & engineering.

I found that the NFPA 86 describes that Class A ovens require a forced ventilation for samples that can produce harmful substances when exposed to higher temperatures.

I was then asked if a muffle furnace would always be considered a Class A, even if it is =E2=80=9Ejust plant tissues and foods" that are put inside.

If I could present more references to them would be great.

Stella Sommer

Sent from my iPhone

On May 11, 2019, at 8:58 PM, Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**lists.princeton.edu> wrote:

What it needs is a small canopy hood and a dedicated powered exhaust duct to the outside.  A muffle furnace shouldn't be in a room without the right kind of exhaust.  A fume hood or an open door with a transfer grill doesn't cut it.  

It is my observation that chemistry fume hoods are the only ventilation systems in many labs.  Yet many labs have equipment that calls for other types of systems designed to the purpose.  That takes a real industrial ventilation engineer to design it rather than engineers who buy off the shelf units and install them.

Monona

-----Original Message-----
From: Richard Palluzi <000006c59248530b-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Sat, May 11, 2019 5:25 pm
Subject: Re: [DCHAS-L] Muffle Furnace Ventilation Requirements

I have encountered dozens of these over the years. The best practice is not
to put them in a hood but to put them on a bench with a small exhaust
immediately over the door so that any fumes are removed when generated or
when the door is opened. Putting them in a hood only blocks the air flow of
the hood and often does a much poorer job of removing the emissions. Also,
since these are often used less frequently, they often migrate to the rear
of the hood and operations begin to be performed in front of them raising
the real potential that they become an ignition source. You might want to
look at the article below for more on the issue of what works (and does not
work) well in a hood.

https://www.linkedin..com/pulse/why-cant-we-put-hood-richard-palluzi/


Richard Palluzi
PE, CSP

Pilot plant and laboratory consulting, safety, design,reviews, and training
www.linkedin.com/in/richardppalluzillc/

Richard P Palluzi LLC
72 Summit Drive
Basking Ridge, NJ 07920
rpalluzi**At_Symbol_Here**verizon.net
908-285-3782

-----Original Message-----
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> On
Behalf Of Stella Julia Sommer
Sent: Saturday, May 11, 2019 9:44 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: [DCHAS-L] Muffle Furnace Ventilation Requirements

Dear all,
I recently started my new position as a instructional support technician at
my local university.
I am also supposed to manage the graduate laboratory. This is where I
encountered a room with a muffle furnace that just vents into the room. It
is set to 550 Deg. Celsius and used to ash plant tissues and food samples.

It is my understanding that those furnaces are supposed to have a separate
ventilation or should at least be located inside of a fume hood
(particulates, smoke, carbon monoxide ...).

Does anyone have a specific reference that describes the issue (standard,
regulation, case study...)?

Thank you very much!

Best Regards,

Stella Sommer

---
For more information about the DCHAS-L e-mail list, contact the Divisional
membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

---
For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org
Follow us on Twitter **At_Symbol_Here**acsdchas

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas