There are two companies (as far as I know) with the technology of a DH III. Erlab licenses their technology to Hamilton and Air Masters. The other is Air Clean who shares their technology with Kewaunee. If you are going to talk to Erlab, you should also talk to Air Clean and you will get a comprehensive answer. I did state in my initial comment that a ductless enclosure is not a substitute for a fume hood The key is to understand the technology and position that technology appropriately to a given application. The filter technology has advanced, yes. Additionally the monitoring technology has advanced. A DH III has the added safety that if a chemical breaks through the filter, it provides a secondary back up protection. With computer technology, a user can consult the hood for a list of chemicals appropriate to the filter in use, and select it as a chemical to be monitored. The hood could also tell you if the chemical to be used is not appropriate for the filter in use. Filters themselves are “tagged” to communicate with the hood to eliminate the chance of an incorrect filter being installed in the hood and the hood “knows” the chemical list for the filter media.
While I do not think a ductless hood is a substitute for a laboratory fume hood, I do believe these products are appropriate for some applications. In the case of an undergraduate program where two primary chemicals are known to be used, this might be a solution. I say might because the liquid volume is important. If you boil off a lot of liquid (even water) you will consume expensive filters quickly. So when you talk to these two companies, ask about the liquid volume. Also ask about the maximum CFM for the hood, and the use of an open flame. Then keep an open mind.
Vice President Engineering and Product Development
Kewaunee Scientific Corporation
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Monona Rossol
Sent: Saturday, March 22, 2014 12:36 PM
Subject: Re: [DCHAS-L] NFPA 45 -- 2015
Sounds like we are not too far apart. I will try to find time to talk to Erlab sometime in the near future.
I also have approved the hoods, as I have said, for common particulates and occasionally for some common solvent use provided it is in liquid amounts similar to that obtained when milking mice.
Monona Rossol, M.S., M.F.A., Industrial Hygienist
President: Arts, Crafts & Theater Safety, Inc.
Safety Officer: Local USA829, IATSE
181 Thompson St., #23
New York, NY 10012 212-777-0062
From: Ken Simolo <simolo**At_Symbol_Here**CHEM.CHEM.ROCHESTER.EDU>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Sent: Sat, Mar 22, 2014 6:05 am
Subject: Re: [DCHAS-L] NFPA 45 -- 2015
You really should talk to the chemists at Erlab. They have done loading factors
for thousands of compounds. They also have a long history of developing systems
for life threatening situations. I was very impressed when I met with them for
a day to discuss my many concerns about using their Green Hoods. But that does
not mean I would make a blanket statement approving their use.
It would be rare that I would recommend a Green Hood as the only hood in any
hood intensive laboratory, even in my teaching labs. Air exchanges are required
and one might as well do that through conventional fume hood. In a more
undefined research lab situation, one has to be extremely careful. There are a
few compounds that are not trapped, carbon monoxide being one common example.
Even for any trapped compound where trace amounts would have a severe negative
health impact, I would be extremely reluctant to allow its use.
Where these hoods are extremely valuable is when they are used to add an extra
layer of safety to an existing situation. We are using them to significantly
increase the level of safety for procedures currently done on an open lab bench.
In a research environment, even doing that has issues. It requires very good
labeling and training of what procedures are appropriate for the Green Hood. It
also requires more follow through to make sure it is being used properly. In
industry, especially in situations where the hood is used in a defined process,
this is much easier to do because the command, safety, and inspection
infrastructure is usually well developed. In the past when it was ok to have
laboratory non-flammables in a non-flammable refrigerator, I did not allow those
types of refrigerators in a laboratory because researchers would routinely put
one or two small bottles of a compound dissolved in a flammable into a non-rated
refrigerator. Green Hoods would be easier t!
o monitor than a refrigerator but the same issues would apply. In my current
state of thinking, I would allow GreenHoods for some very well defined and
easily monitored processes. If, for example, a researcher wanted some Green
Hoods in a lab to place their rotovaps in, I would allow that since these
rotovaps are usually located on a lab bench. Inspecting their appropriate use
would be pretty easy - if a reaction is going on in that hood or they are
storing chemicals in it, that would be a violation of the agreement. I might
also allow them for labs that do their work on a lab bench now and have no
capability to add conventional fume hoods. Fortunately, that is not an issue
for our building.
We have an ~25% turnover in our researchers each year. Add to that the fact
that the course of academic research can change abruptly with no notice makes me
leery of using Green Hoods as a replacement for a conventional academic research
hood. But I do believe they are an excellent solution in specific
circumstances. I am extremely comfortable in how we have used them and I am
quite happy with how they have significantly increased our safety without adding
a huge environmental/energy cost while doing so.
Previous post | Top of Page | Next post