11-10-2010, 12:36 AM
Asbestos in radios, what to do about it
1. At present, asbestos is known to be hazardous only if inhaled. Although there is some ongoing study on ingestion, the results are so far not alarming. Certainly less alarming than the results on arsenic, lead or cadmium.
2. Asbestos will become airborne only if friable (easily broken into small pieces). It becomes friable primarily if disturbed. There are three significant forms of asbestos as it was commonly used in consumer articles: Chrysotile, Amosite, and Crocidolite. Of these, chrysotile (white asbestos) is the most likely fiber to be found in that mat in your radio.
3. Asbestos that remains in place or can be made to remain in place is NOT hazardous.
Safing (encapsulating): Most (not all) of the asbestos used in domestic radios is included in a soft mat, either woven (rare) or non-woven (common). Usually it is held together with either a cementicious or gypsum-based binder together with several other fibers. The trick is to replace the binder with a more permanent and less mechanically vulnerable material. The EPA and OSHA recognize many sorts of encapsulants, including the binders used in both Duco Cement and Amberoid Cement. (Personal comment: I recommend Amberoid for its distinct color and the fact that I find it somewhat easier to use and less expensive that Duco. But the processes are identical. Amberoid will also maintain the insulating properties of asbestos, I am not sure if Duco will do the same.)
Mix the material of choice (Duco or Amberoid) with equal parts by volume of Acetone and soak this diluted material into the asbestos mat. It will re-glue the mat in place and bind all the fibers together. Allow to dry and soak again. Do this work away from flame or any source of flame. Do this work outdoors if possible. Do not attempt to brush, clean or vacuum the mat prior to treatment. Glue ALL of it down.
The times when the insulating mat are most likely to be disturbed are when the chassis is removed or reinstalled in a radio. Given that the original binders were not all that effective in the first place, and that they were made with deliquescent materials (gypsum or portland cements) it is very likely that some of the fibers will have become loose over the years, and may be disturbed when the chassis is moved or removed. If mice have inhabited the radio, this is a certainty. So, some initial cautions MUST be taken. And given that some here will neither admit to the hazard nor take any precautions, and that others here may not have the financial resouces to "have it done", what I suggest here is not offered as a way to eliminate a significant risk, but a way to reduce it at least in part.
First: Work out of doors. If you choose not to believe in any risk, it is still unfair to introduce asbestos into a house (or household) where it may remain a hidden hazard forever. Work over a large leaf-and-lawn bag if possible.
Tools:
1. Good particle mask. Must be effective from .1 to 10 microns (a human hair is about 50 microns in diameter). Because asbestos fibers are small and light, they can be suspended in the air for long periods. This is NOT a paper painter's mask. But once obtained, may be retained for multiple uses.
2. Small spray bottle filled with a 15:1 water-to-dish-soap solution. You will need a couple of ounces for the process, and about a pint at the end to soak the debris.
3. Strong paper towels... those that will not dissolve in soapy water.
4. Small, soft-bristled disposable brush. About 1/2" wide or smaller with at least 1" bristles.
5. Single-edge razor blade (not always necessary).
Spray the soap solution around the base of the chassis before removal. Make sure that the entire perimeter where it touches the asbestos is saturated and damp. This will hold the fibers from becoming airborne as the chassis is removed.
Remove the chassis carefully. Use the razor blade if necessary to cut loose the mat from the chassis. The idea is to leave the mat in place and not on the chassis.
Look on the chassis. If there are any visible particles of the mat on or in it, they must be collected and removed. For this, you will use the towels, the brush and PLENTY of the soapy water. A wet asbestos fiber will not become airborne. Soap is the wetting agent. Take your time and be thorough. Clean ANYTHING, even spider-webs or other material from the chassis. Be sure that it is clean.
Gently spray the inside of the radio cabinet with the soapy water. This would be those areas around but not covered by the mat. Wipe this down with the paper towels and repeat. The idea here is to capture any bits of asbestos that may have come loose from the mat.
Allow the cabinet to dry thoroughly. Soak the now-dry mat with the safing material as above. While the cabinet is drying, collect all the other detritus (brush, towels, razor, whatever) into the garbage/leaf & lawn bag. Pour the remaining soap solution over it so that it becomes a soapy mess. Seal the bag and bag it a second time. If there are ANY leaks in the first bag, bag it a third time. Dispose of the bags with your township's hazardous materials regulations, or in a regular landfill, NOT an incinerator or where the trash may be incinerated. Remove, double-bag and dispose of the mask filter also. You will use a new one for each session.
A bit long-winded as always, but the proverbial ounce of prevention covers many pounds of care in this case.
Above section on asbestos written by:
Peter Wieck
1. At present, asbestos is known to be hazardous only if inhaled. Although there is some ongoing study on ingestion, the results are so far not alarming. Certainly less alarming than the results on arsenic, lead or cadmium.
2. Asbestos will become airborne only if friable (easily broken into small pieces). It becomes friable primarily if disturbed. There are three significant forms of asbestos as it was commonly used in consumer articles: Chrysotile, Amosite, and Crocidolite. Of these, chrysotile (white asbestos) is the most likely fiber to be found in that mat in your radio.
3. Asbestos that remains in place or can be made to remain in place is NOT hazardous.
Safing (encapsulating): Most (not all) of the asbestos used in domestic radios is included in a soft mat, either woven (rare) or non-woven (common). Usually it is held together with either a cementicious or gypsum-based binder together with several other fibers. The trick is to replace the binder with a more permanent and less mechanically vulnerable material. The EPA and OSHA recognize many sorts of encapsulants, including the binders used in both Duco Cement and Amberoid Cement. (Personal comment: I recommend Amberoid for its distinct color and the fact that I find it somewhat easier to use and less expensive that Duco. But the processes are identical. Amberoid will also maintain the insulating properties of asbestos, I am not sure if Duco will do the same.)
Mix the material of choice (Duco or Amberoid) with equal parts by volume of Acetone and soak this diluted material into the asbestos mat. It will re-glue the mat in place and bind all the fibers together. Allow to dry and soak again. Do this work away from flame or any source of flame. Do this work outdoors if possible. Do not attempt to brush, clean or vacuum the mat prior to treatment. Glue ALL of it down.
The times when the insulating mat are most likely to be disturbed are when the chassis is removed or reinstalled in a radio. Given that the original binders were not all that effective in the first place, and that they were made with deliquescent materials (gypsum or portland cements) it is very likely that some of the fibers will have become loose over the years, and may be disturbed when the chassis is moved or removed. If mice have inhabited the radio, this is a certainty. So, some initial cautions MUST be taken. And given that some here will neither admit to the hazard nor take any precautions, and that others here may not have the financial resouces to "have it done", what I suggest here is not offered as a way to eliminate a significant risk, but a way to reduce it at least in part.
First: Work out of doors. If you choose not to believe in any risk, it is still unfair to introduce asbestos into a house (or household) where it may remain a hidden hazard forever. Work over a large leaf-and-lawn bag if possible.
Tools:
1. Good particle mask. Must be effective from .1 to 10 microns (a human hair is about 50 microns in diameter). Because asbestos fibers are small and light, they can be suspended in the air for long periods. This is NOT a paper painter's mask. But once obtained, may be retained for multiple uses.
2. Small spray bottle filled with a 15:1 water-to-dish-soap solution. You will need a couple of ounces for the process, and about a pint at the end to soak the debris.
3. Strong paper towels... those that will not dissolve in soapy water.
4. Small, soft-bristled disposable brush. About 1/2" wide or smaller with at least 1" bristles.
5. Single-edge razor blade (not always necessary).
Spray the soap solution around the base of the chassis before removal. Make sure that the entire perimeter where it touches the asbestos is saturated and damp. This will hold the fibers from becoming airborne as the chassis is removed.
Remove the chassis carefully. Use the razor blade if necessary to cut loose the mat from the chassis. The idea is to leave the mat in place and not on the chassis.
Look on the chassis. If there are any visible particles of the mat on or in it, they must be collected and removed. For this, you will use the towels, the brush and PLENTY of the soapy water. A wet asbestos fiber will not become airborne. Soap is the wetting agent. Take your time and be thorough. Clean ANYTHING, even spider-webs or other material from the chassis. Be sure that it is clean.
Gently spray the inside of the radio cabinet with the soapy water. This would be those areas around but not covered by the mat. Wipe this down with the paper towels and repeat. The idea here is to capture any bits of asbestos that may have come loose from the mat.
Allow the cabinet to dry thoroughly. Soak the now-dry mat with the safing material as above. While the cabinet is drying, collect all the other detritus (brush, towels, razor, whatever) into the garbage/leaf & lawn bag. Pour the remaining soap solution over it so that it becomes a soapy mess. Seal the bag and bag it a second time. If there are ANY leaks in the first bag, bag it a third time. Dispose of the bags with your township's hazardous materials regulations, or in a regular landfill, NOT an incinerator or where the trash may be incinerated. Remove, double-bag and dispose of the mask filter also. You will use a new one for each session.
A bit long-winded as always, but the proverbial ounce of prevention covers many pounds of care in this case.
Above section on asbestos written by:
Peter Wieck
