Guest guest Posted March 20, 2006 Report Posted March 20, 2006 and others, Question. How do you sample when blasting techniques have been used? The reason I ask is the multiple forces involved should destroy the viability of spores. So culturing of the " dust " should be negative - as in zero? This begs the question for microscopy. However, the particulate debris of the " dust " has increased and perhaps the spores and fragments have been pulverized to particles too small to identify as fungal. In other words, the conventional markers of the existence of mold growth have been destroyed but the proteins, enzymes and glucans, etc responsible for health effects are still present. Do we know (has anyone done the research?) to verify that blasting techniques actually remove/destroy the components of growth rather than just destroy the assumed evidence? Carl Grimes Healthy Habitats LLC ----- > Don, Bill and others interested in media blasting techniques for mold > remediation: > > We work with and provide hands-on training for remediation > professionals in using media blasting techniques. It has become one > of the more common methods for mold removal from wood framing and > concrete surfaces and it is very successful. There are limitations > regardless if you are using dry ice or baking soda and wanted to > share what we have found. > > Although there is less clean-up time associated with dry ice, there > are some other significant limitations. The main one being the risk > of oxygen depletion when working in a confined space (e.g. crawl > spaces). Oxygen monitors are critical. There is also a skin hazard > and the appropriate PPE must be worn. There are also limitations > with the availability of this medium because it needs to be ordered > and delivered on an as needed basis for each job. That becomes a > bigger issue when working in hot / humid climates and being able to > maintain the integrity of the ice. There have also been some > challenges with finding vendors to provide the media. > > The size of the ice pellets will also affect the finished appearance > of the surface. Meaning the larger the pellets, the deeper the > dimples left in the wood surface. > > Soda blasting (baking soda) obviously generates more dust and debris > which increases clean-up time and efforts. But some of the > advantages are that there are minimal health and safety risks. > > The media can be maintained, stored and used on an as needed basis for > projects. It is generally easier to find a vendor for this medium > and it is less expensive than dry ice. The surface of the blasted > materials are smoother and have a like-new appearance. > > The equipment requirements are different for each of the two media and > there is an investment cost associated. By using media blasting it > has made remediation contractors much more efficient. It drastically > reduces the costs because it decreases the amount of labor needed. > What it would take for a crew of 5 to do in a period of a week can be > done in 1 day with a crew of 2 or three. Typically, labor is the > greatest cost factor in remediation projects. > > I hope that this information is helpful to those of you just starting > to use this technique and for those who are contemplating using it. > > > Indoor Air Management, Inc. > Quote
Guest guest Posted March 23, 2006 Report Posted March 23, 2006 Cassidy, My study of an independent finalization of dry ice treatment (not blasting), using air and tape-lift samples, identified a great difference in analysis between various projects. When I identify a remediation project where the air or surface data is questionable, I go back to the contractor and ask: Did you complete the project in containment? Was there a laminar flow of makeup air going across the treated surface? Was there a dust capture zone? How much of a dust problem was created in indoor air? Quite often what I determine, the environmental controls of the remediation project are suspect which leads to a particulate debris field everywhere, similar to what you discussed. The laboratory data reflects this condition. Bottom line: better training of the remediation contractor and the use of engineering controls seems to eliminate many of the problems associated with a surface blasting or treatment media. Moffett Re: Dry Ice - Question Amy and Group: I personally collected and analyzed dozens of tape lift samples following an extensive remediation using dry-ice blasting, followed by HEPA vac and damp wiping. What I found is that a very high level of spores and hyphal fragments were present on surfaces following these procedures. And from my experience, the level was much higher than when only HEPA and damp wiping is used (does dry-ice blasting embed fungal particles into crevices?). What was disturbing is that the entire bottom side of the exposed subfloor of the second floor (dry ice blasting occurred on the first floor) was saturated in spores and hyphal fragments. The growth did not occur on these surfaces! I can only speculate that the extremely elevated levels of hyphal fragments were a result of the dry-ice blasting process applied to the damaged wood framing and exterior sheathing of the walls. Note: The 2nd floor subfloor had never underwent HEPA or wiping prior to sampling. And after these processes...the darn subfloor still had very elevated spore/hyphae levels! In this case, the remediation contractor was competent and the machine s used were, supposedly, in good order. Cassidy Kuchenbecker s Engineering > > In response to Carl Grimes's question about verification testing after dry ice remediation I thought I'd share my own experience. > > A few minutes ago I received laboratory results from surface sampling I conducted on plywood sheathing in an attic as part of a post-remediation verification inspection (after dry ice method). I don't know whether or not the contractor used the dry ice method correctly (apparently the dry ice machine is new to him) but I do know that the analysis clearly qualified and quantified several types of mold spores on the post-remediation samples (microscopy analysis in this case). > > Amy Siedlecki > President > The Mold Reporters Inc. > Indoor Environmental Consultants > Re: Dry Ice - Question > > > and others, > > Question. How do you sample when blasting techniques have been used? > The reason I ask is the multiple forces involved should destroy the > viability of spores. So culturing of the " dust " should be negative - > as in zero? This begs the question for microscopy. However, the > particulate debris of the " dust " has increased and perhaps the spores > and fragments have been pulverized to particles too small to identify > as fungal. In other words, the conventional markers of the existence > of mold growth have been destroyed but the proteins, enzymes and > glucans, etc responsible for health effects are still present. Do we > know (has anyone done the research?) to verify that blasting > techniques actually remove/destroy the components of growth rather > than just destroy the assumed evidence? > > Carl Grimes > Healthy Habitats LLC > > ----- > > Don, Bill and others interested in media blasting techniques for mold > > remediation: > > > > We work with and provide hands-on training for remediation > > professionals in using media blasting techniques. It has become one > > of the more common methods for mold removal from wood framing and > > concrete surfaces and it is very successful. There are limitations > > regardless if you are using dry ice or baking soda and wanted to > > share what we have found. > > > > Although there is less clean-up time associated with dry ice, there > > are some other significant limitations. The main one being the risk > > of oxygen depletion when working in a confined space (e.g. crawl > > spaces). Oxygen monitors are critical. There is also a skin hazard > > and the appropriate PPE must be worn. There are also limitations > > with the availability of this medium because it needs to be ordered > > and delivered on an as needed basis for each job. That becomes a > > bigger issue when working in hot / humid climates and being able to > > maintain the integrity of the ice. There have also been some > > challenges with finding vendors to provide the media. > > > > The size of the ice pellets will also affect the finished appearance > > of the surface. Meaning the larger the pellets, the deeper the > > dimples left in the wood surface. > > > > Soda blasting (baking soda) obviously generates more dust and debris > > which increases clean-up time and efforts. But some of the > > advantages are that there are minimal health and safety risks. > > > > The media can be maintained, stored and used on an as needed basis for > > projects. It is generally easier to find a vendor for this medium > > and it is less expensive than dry ice. The surface of the blasted > > materials are smoother and have a like-new appearance. > > > > The equipment requirements are different for each of the two media and > > there is an investment cost associated. By using media blasting it > > has made remediation contractors much more efficient. It drastically > > reduces the costs because it decreases the amount of labor needed. > > What it would take for a crew of 5 to do in a period of a week can be > > done in 1 day with a crew of 2 or three. Typically, labor is the > > greatest cost factor in remediation projects. > > > > I hope that this information is helpful to those of you just starting > > to use this technique and for those who are contemplating using it. > > > > > > Indoor Air Management, Inc. > > > > > > > > > > FAIR USE NOTICE: > > This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available in our efforts to advance understanding of environmental, political, human rights, economic, democracy, scientific, and social justice issues, etc. We believe this constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes. For more information go to: http://www.law.cornell.edu/uscode/17/107.shtml. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. > > > > Quote
Guest guest Posted March 24, 2006 Report Posted March 24, 2006 Carl: My last message may have seemed more against dry-ice blasting than it was meant. Dry-ice blasting is a great remediation tool. However, I am concerned with, possibly, how some techs or how some of the tools operate. In the case I stated, the spores and hyphal fragments coated (not simply littered) both the surfaces remediated and the non-remediated surfaces. They were definetely the same genera and definetely from the water-damaged surfaces. While we have performed post-remediation sampling following dry-ice blasting before (which the surface were acceptable), this was the first time I had taken and personally viewed the tape lifts. So, naturally, my wariness is heightened till I can perform the same procedure again, and find low levels of fungal particles on the lifts. Cassidy Kuchenbecker s Engineering > > Amy and others, > > Are you finding identifiable spores left on the original surface or > in the " dust " generated that settles elsewhere? > > Carl Grimes > Healthy Habitats LLC > > ----- > > In response to Carl Grimes's question about verification testing after > > dry ice remediation I thought I'd share my own experience. > > > > A few minutes ago I received laboratory results from surface sampling > > I conducted on plywood sheathing in an attic as part of a > > post-remediation verification inspection (after dry ice method). I > > don't know whether or not the contractor used the dry ice method > > correctly (apparently the dry ice machine is new to him) but I do know > > that the analysis clearly qualified and quantified several types of > > mold spores on the post-remediation samples (microscopy analysis in > > this case). > > > > Amy Siedlecki > > President > > The Mold Reporters Inc. > > Indoor Environmental Consultants > > Re: Dry Ice - Question > > > > > > and others, > > > > Question. How do you sample when blasting techniques have been used? > > The reason I ask is the multiple forces involved should destroy the > > viability of spores. So culturing of the " dust " should be negative - > > as in zero? This begs the question for microscopy. However, the > > particulate debris of the " dust " has increased and perhaps the > > spores and fragments have been pulverized to particles too small to > > identify as fungal. In other words, the conventional markers of the > > existence of mold growth have been destroyed but the proteins, > > enzymes and glucans, etc responsible for health effects are still > > present. Do we know (has anyone done the research?) to verify that > > blasting techniques actually remove/destroy the components of growth > > rather than just destroy the assumed evidence? > > > > Carl Grimes > > Healthy Habitats LLC > > > > ----- > > > Don, Bill and others interested in media blasting techniques for > > mold > remediation: > > We work with and provide hands-on training > > for remediation > professionals in using media blasting techniques. > > It has become one > of the more common methods for mold removal > > from wood framing and > concrete surfaces and it is very > > successful. There are limitations > regardless if you are using dry > > ice or baking soda and wanted to > share what we have found. > > > > Although there is less clean-up time associated with dry ice, there > > > are some other significant limitations. The main one being the > > risk > of oxygen depletion when working in a confined space (e.g. > > crawl > spaces). Oxygen monitors are critical. There is also a > > skin hazard > and the appropriate PPE must be worn. There are also > > limitations > with the availability of this medium because it needs > > to be ordered > and delivered on an as needed basis for each job. > > That becomes a > bigger issue when working in hot / humid climates > > and being able to > maintain the integrity of the ice. There have > > also been some > challenges with finding vendors to provide the > > media. > > The size of the ice pellets will also affect the > > finished appearance > of the surface. Meaning the larger the > > pellets, the deeper the > dimples left in the wood surface. > > > > Soda blasting (baking soda) obviously generates more dust and debris > > > which increases clean-up time and efforts. But some of the > > > advantages are that there are minimal health and safety risks. > > > > The media can be maintained, stored and used on an as needed basis > > for > projects. It is generally easier to find a vendor for this > > medium > and it is less expensive than dry ice. The surface of the > > blasted > materials are smoother and have a like-new appearance. > > > > The equipment requirements are different for each of the two > > media and > there is an investment cost associated. By using media > > blasting it > has made remediation contractors much more efficient. > > It drastically > reduces the costs because it decreases the amount > > of labor needed. > What it would take for a crew of 5 to do in a > > period of a week can be > done in 1 day with a crew of 2 or three. > > Typically, labor is the > greatest cost factor in remediation > > projects. > > I hope that this information is helpful to those of > > you just starting > to use this technique and for those who are > > contemplating using it. > > > Indoor Air Management, > > Inc. > > > > > > > > > > > > > > > > > FAIR USE NOTICE: > > > > This site contains copyrighted material the use of which has not > > always been specifically authorized by the copyright owner. We are > > making such material available in our efforts to advance > > understanding of environmental, political, human rights, economic, > > democracy, scientific, and social justice issues, etc. We believe > > this constitutes a 'fair use' of any such copyrighted material as > > provided for in section 107 of the US Copyright Law. In accordance > > with Title 17 U.S.C. Section 107, the material on this site is > > distributed without profit to those who have expressed a prior > > interest in receiving the included information for research and > > educational purposes. For more information go to: > > http://www.law.cornell.edu/uscode/17/107.shtml. If you wish to use > > copyrighted material from this site for purposes of your own that go > > beyond 'fair use', you must obtain permission from the copyright > > owner. > > > > > > > > Quote
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