Nitrogen is not totally inert, reacts with some metals that can be used as pigments.. Fungi acceleration is after opening the chamber, not in the chamber. More researchs needs to be done in this area, hopefully it will be. Bill In a message dated 10/13/2010 9:53:11 A.M. Eastern Daylight Time, step...@stephan-schaefer.com writes:
Re: Choice of Argon vs. Nitrogen for the treatment and control of insect infestation In reference to the questionable statement, that "inert" gases other than argon "are likely to foster fungal growth" I think it is important to clarify some issues regarding the use of either gas for the control of insect pests and the influence on microbiological activity. First of all, both gases are entirely inert and scientific research has proven their full efficacy in eliminating all types of insect pests in all life stages (given that specific conditions are being maintained and controlled during treatment). Second, fungal germination and growth depends upon the substrate and ambient conditions. Actually, most of us will intuitively know that fungal and bacterial development only occurs at higher humidity levels and where there is lack of ventilation. Actually, the threshold level lies somewhere around 70% relative humidity. Below about 65% there is literally no risk for fungal and bacterial proliferation. My third and probably most important point is why nitrogen anoxia will "foster" fungal growth although it is known to be a strong inhibitor of microbiological activity?? From scientific research we only know, that some anaerobic microorganisms are able to survive under "nitrogen anoxia" conditions. The other more practical consideration is that during anoxia treatments, the humidity inside the "bubble" should always be controlled and certainly kept below 65% RH, so the likelihood of fungal growth inside the bubble under anoxic conditions is absolutely zero, whether nitrogen or argon is used. Furthermore, we are only speaking about a treatment period of approximately 30 days, the time needed to kill all insects in all developmental stages. Therefore, I think the issues of fungal growth are much more related to the environment and ambient conditions where the objects in question are being kept at all times, rather than the short period inside a bubble where they remain during an anoxic treatment and where conditions should be controlled anyway. In own experiments, where I sealed wet paper and books in gas barrier bags with Ageless oxygen absorbers, where the remaining gas is mainly nitrogen, no fungal growth was noticeable after about 50 days. The bags were kept at about 20 - 22 °C and the control that was sealed with atmospheric air inside has shown noticeable fungal and probably bacterial growth after about 72 hours. This in itself proves that fungal growth is not an issue with respect to the choice of the gas (argon or nitrogen) when considering anoxia treatment in order to eliminate insect pests. Additionally, it may be interesting to consider cost, as argon is a lot more expensive than nitrogen which is the most abundant gas in our atmosphere. I would be very interested in hearing other peoples comments on the subject. Stephan Schäfer -------------------------------------------------------- STEPHAN SCHÄFER Conservação e Restauração ltda. Rua Manduri, 400 - Jd. Paulistano 01457-020 São Paulo, Brazil Tel./Fax: 00 xx 11 3816-0489 Cel: 00 xx 11 8366-0230 e-mail: _step...@stephan-schaefer.com_ (mailto:step...@stephan-schaefer.com) --------------------------------------------------------- --------------------------------------------------------- Prof. Dipl. Rest. Stephan Schäfer Universidade Nova de Lisboa (UNL) Faculdade de Ciências e Tecnologia (FCT) Departamento de Conservação & Restauro 2829-516 Caparica - Lisboa PORTUGAL e-mail: _sc...@fct.unl.pt_ (mailto:sc...@fct.unl.pt) --------------------------------------------------------- At 19:22 08.10.2010, you wrote: Dear Dr. Diego; The most reasonable option is to use anoxic system, specially with argon protocol. This is due to the fact other "inert" gases are likely to foster fungal growth. Please give me a call when you can, and I'll be pleased to help you as I'm using argon's anoxia systems here in Brazil for over ten years. Best regards, Ulisses Mello, Dip. Cons., PG Art Care do Brasil Mobile: +55 21 98979074 Office: +55 21 25587749 2010/10/8 Revelez, Marcia A. <_mreve...@ou.edu_ (mailto:mreve...@ou.edu) > Forwarding this for a colleague. Please respond to Deigo (email below). Thanks! ---------------------------------------------------------------------------- Marcia A. Revelez Collection Manager Department of Mammalogy Division of Collections and Research Sam Noble Oklahoma Museum of Natural History University of Oklahoma 2401 Chautauqua Norman, OK 73072 Phone: 405-325-7988 Fax: 405-325-7699 Begin forwarded message: From: Diego Astua de Moraes <_d.a.mor...@gmail.com_ (mailto:d.a.mor...@gmail.com) > Date: October 8, 2010 12:43:07 PM CDT To: <_ mamma...@si-listserv.si.edu_ (mailto:mamma...@si-listserv.si.edu) > Subject: Fumigating cabinets - bug infestation Reply-To: Mammalian Biology <_ mamma...@si-listserv.si.edu_ (mailto:mamma...@si-listserv.si.edu) > Hi all. In a matter of days bugs have started to show in our skin cabinets. According to our entomologist they should be beetles that feed on wood or cellulose (sorry if the family names escapes right now), but other entomology curators have seen these eating almost everything in other regions of Brazil. Regardless of what they are, I want them all dead now! In short, I need to get rid of them as quickly as possible, before the damage increases. Freezing is unpractical at this point, too many specimens and too little freezer space (we are talking about 3 cabinets with beetles confirmed, and about 3-4 others still intact, but that I want to protect as well). I´ve had suggestions of fumigating the entire cabinets using PDB balls, but I can´t seem to be able to find those here quickly. Our entomology colleagues have suggested to use ethyl acetate and seal the cabinets so that it kills adults and larvae. My main doubt is if there is any knowledge that this may damage severely the skins (because if i don´t do anything quickly they are being damaegd anyway!), and if this would be enough. I am not sure about the amounts, I´ve read of a cotton ball in ethyl acetate to fumigate a small container to kill the ectoparasites of a single specimen, bu what about a whole cabinet? And how long should it be kept sealed? Or are there any other quick solutions, remembering that many "easy" solutions are now radily found around here....! thanks for any help. Diego Diego Astúa de Moraes, D.Sc. Departamento de Zoologia - CCB Universidade Federal de Pernambuco Av. Professor Moraes Rego, s/n. Cidade Universitária 50670-420 Recife, PE Fone(fax): (81) 2126-8353 email: _d.a.mor...@gmail.com_ (mailto:d.a.mor...@gmail.com) - _diegoas...@ufpe.br_ (mailto:diegoas...@ufpe.br) _http://www.ufpe.br/mastozoologia/_ (http://www.ufpe.br/mastozoologia/)
