Lori Larsen on thu 6 may 99
Long, so if you are not interested just skip ahead.
I had responded directly to Julie Kent's first post about paper
disposable filters and respirators as I my main work is with an
environmental consulting company that specializes amongst other things in
occupation hygiene. Julie's posts are included at the end so you can
refresh your memory. After she posted again I realized that I was
assuming a whole lot about respirators and dust masks and decided to get
some straight information on the whole topic.
As many people have mentioned, the dust in studios is largely from clay
and clay contains silicon. Inhaling silicon can cause coughing,
wheezing, decreased pulmonary function, progressive respiratory symptoms
and eventually silicosis. It is also an eye irritant and is considered
carcinogenic. This information is from Niosh Pocket Guide to Chemical
Hazards available on the web at http://www.cdc.gov/niosh/npg/npgd0553
Look up silica, crystalline (as respirable dust). That same source says
that the time weighted recommended exposure limit is 0.05mg/cubic metre.
More info on exactly what part of the silica is harmful, the IDHL or
immediately dangerous to life or health, is also listed.
The Niosh guide has recommendations for respirator selection. If you are
to be exposed to 0.5mg/cubic metre (note this is 10 times the maximum
time weighted exposure limit) you are to use a HIE (APF 10) meaning any
air-purifying respirator with a high-efficiency particulate filter. APF
stands for Assigned Protection Factor. APF > (Workplace Airborne
Concentration / NIOSH Recommend Exposure Limit) If you are exposed to
1.25 mg/cubic metre of silica dust, you should be wearing a
PAPRHIE/SA:CF(APF 25) meaning a powered air-purifying respirator with a
high-efficiency particulate filter operated in a continuous flow mode.
The 1995 Niosh Respiratory use policy states "It is emphasized that the
APF in the above criterion is the minimum recommended by NIOSH. The use
of respirator types with higher APFs is preferred. Specifically, NIOSH
recommends always selecting the respirator type with the highest APF that
is compatible with the conditions of each particular workplace. This is
particularly true for workplace exposures to carcinogens since there may
be no exposure level below which there is no risk of disease. When
respirators are used to reduce exposure to carcinogens, the risk of
disease will decrease as respirators with higher APFs are selected. It is
further emphasized that the use of respirators in no way eliminates the
need to reduce ambient workplace exposures to the lowest feasible level
through the use of process changes and engineering controls."
http://www.cdc.gov/niosh/respuse.html
How do you know what filter you should be wearing?? Good question. I
searched the web and picked my co-workers brains for this one as now it
becomes confusing. Like all good scientists, my co-workers said, have
you tested the air? Of course not, us studio potters don't have the
corporate budgets to hire a consultant firm like the one I work for. So
we make assumptions in order to get some sort of answer. You know what
assume means...making asses out of "u" and "me". So keeping that in
mind, we can "safely" state that we probably are not in an atmosphere
that exceeds more than ten times that of our acceptable time weighted
average exposure limit of 0.05mg/cubic metre.
Great now we know what we need to get a HIE(APF10) so what is that. Well
an air purifying respirator comes in many forms. It is a device that you
can draw air through that will filter particles and is usually powered by
yourself by breathing in (and out). This class includes half face
respirators, you know the soft rubber ones with two cartridges on either
side AND includes the disposable throw away paper masks if they are rated
properly (the ones that everyone has questions about). The new public
health regulations 42 CFR 84 (in the USA only) state that to protect
against dusts and mists only you must have an N (not resistant to oil)
95, 97 or 99.97 percent efficient filter. The old ratings for filters
used to be Part 11 code filters. Now Niosh also states "Because
research shows that particles sized 2 micrometers or smaller can
penetrate some DM [dust & mist respirator (APF=5)]and DFM [dust & mist
respirator with a full facepiece (APF=10)] filters, these Part 11 filters
should be used only when the mass median aerodynamic diameter (MMAD) is
known to be greater than 2 micrometers [NIOSH 1995]. If this diameter is
less than 2 micrometers or is unknown, a Part 11 HEPA filter or any Part
84 filter should be used. In Canada, according to my co-workers, only the
half face respirators with HEPA cartridges are adequate.
What is the difference between the two?
Well the rubber half face respirators with high efficiency filters have
an efficiency rating of 99.97 percent when using filters are commonly
known as HEPA - High efficiency filters for aerosol. Yes a HEPA filter
qualifies as a HIE filter. A half face respirator can be fit tested to
ensure that it is fitting properly and that all the air that you breath
is going through those filters. This respirator IS more effective than
the dust masks because it can create a seal on your face BUT it MUST be
fitted properly.
The dust masks that Julie mentioned the 3M 8210 N95 meets NIOSH 42 CFR 84
N95 requirements. You can look at this mask at
http://www.plasticsnet.com/Scripts/ProductCat/ProductDisplay.cfm?ReqSeller
Id=0F51C504067411D1B70E0060970EA55A&ReqCoHandle=imscompany&ReqProductId=99
465F90C02F11D2BA300060970EA287&ReqHierId=A2FF7A53BF5811D2BA300060970EA287
(sorry for the long URL, just click on it) This mask will filter 95
percent of the dust particulates to 0.3um MMAD (mass median aerodynamic
diameter) Sodium Chloride Particle challenge. Sounds good right? Not
exactly. This mask will filter all air that goes through the filter at
that rate. What about the air that escapes in around the sides??? I
sort of figured out that the air that escapes in from the sides is just
one of the reasons why it is rated at 95 percent. My co-worker
interpreted even differently than what I gleaned from the online NIOSH
and OSHA articles,. He thought that mask would only have a 95 percent
efficiency rating if was fitted perfectly and there is NO WAY to test to
make sure that it fits well. Short of crazy gluing it on to your face
(which would hurt when you took it off) there is no way to ensure a
perfect fit. Well you may be able to fit test it using irritant smoke
but chances are that you won't have access to this.
So there should be a big "ah ha!" here. Do I see light bulbs going on
every where? My it IS bright! But I hear you say, NIOSH just say
particulate filters and don't specify which exactly to use. Well they do
admit that the minimum for use should be a 95 percent efficient filter
but readily admit that such filters should be tested to ensure that they
fit. So in reality, the best respirator is the cartridge ones that you
can at least do positive and negative air pressure checks yourself and
can then get an irritant smoke test. (the banana oil test is only for
filters with organic cartridges!)
The cost issue is bogus. The dust mask is intended as a one use, being
one eight hour shift. If you use it less than that, you could probably
use it a couple of times before throwing it out. You should keep it
clean and in its original shape. Lets say you are using these masks and
go through one per week. That $3 times 52 weeks which is $156. For a
half face respirator you pay an initial $35-$50 for the mask itself then
the HEPA filters cost you about $7 to $10 a pair and the rule of thumb is
to replace them every six months sooooo.. lets see here about $70 for a
half face respirator for a year. MUCH less, MUCH more protection if
properly fitted and fit tested. Your supplier should be able to get you
fit tested for the cost of purchasing the filter. If not go elsewhere.
About that 4 percent comment in the article. I don't know about you, but
4 % may just mean the difference from feeling healthy and being sick.
Again your choice.
Fit testing for half face respirators has been covered adequately in
dribs and drabs over the last few days. I hope that all this helps you
make decisions. Now I am going to find that article in Pottery Making
Industry and email this to the author of it.
JULIE'S FIRST POST
Subject: Re: Small dust masks
----------------------------Original message----------------------------
I wanted to address this whole dust mask issue because I have had an
offer
from a relative (who works in light industry) to get me a good dust mask
at
cost. Of course, he needs to know what size I am. If I go to Home Depot
and try on whatever they have on the shelf will narrowing it down to
small,
medium or large be sufficient? Or does mask size vary enough from brand
to
brand to make this kind of guesswork useless?
And while we're on the subject of dust masks, I was very confused by the
article "Respirators for Potters" in this spring's Pottery Making
Illustrated by Jeff Zamek which listed a paper dust mask as a "first
choice....for protection against airborne particles found in the pottery
studio." Did anyone else stop short at reading that? I was under the
impression that it is very important to have that respirator seal against
your face, otherwise you are breathing in particles around the sides
anyway. The article states that there is a mere difference of 4 percent
(the paper mask filtering 95 percent of particles, and the highest rated
NIOSH particle respirator filtering 99.97 percent)
Now, I have been grumbling on and off about the aforementioned disposable
paper dust masks that are in use at our community art center -- mostly
because it was recommended we re-use them by putting them in a plastic
bag
(!). I refused and toss mine out after one use (cleaning shelves or
grinding ware outside). However, I also refuse to mix glazes inside
unless
they buy me my own particle respirator, because I just feel like those
little flimsy paper things are not enough to stand between me and major
lung problems (as an ex-smoker and an ex-asthma sufferer I try to be
extra
careful). Am I wrong to take this position?
I also shuddered at the opening line in the article where he mentions
sweeping his studio -- who does that? I was under the impression that
all
studio cleaning should be wet cleaning.
Interested in other (older and wiser) people's responses to this
article....
Julie Kent
JULIE'S SECOND POST
Subject: Dust masks, cleanliness & other safety concerns
----------------------------Original message----------------------------
Thanks to everyone who has replied to my post on dust masks/respirators.
I
still am wondering if I *can* get an ok seal on the 3M 8210 that is used
in
our community studio. It's going to take me a while to do my homework,
find my own respirator and get it fitted properly (and thanks for the
suggestions).
Meanwhile, I still have to go to work at the clay center and do my job.
And the most immediate concern is not the filter itself (which has a 95%
efficiency rating, which isn't bad), but the fit of the filter on my
face.
So the question becomes, how can I be certain that the filter is doing
it's
job while I'm bending over and contorting myself to clean those shelves?
Although the ideas of smelling banana oil or a saccharine hood are great
for companies that test this kind of thing regularly, what might be a
practical way of testing the seal myself? I don't know of any
manual/textbook that covers this -- it goes down in the "just figure it
out" section that so much of pottery is relegated to.... What if I light
a
candle, blow it out, then put on the mask and see if I can smell the
smoke?
Or perhaps some airborne confectioner's sugar might be a better test
because of the fine particles that I would be able to taste? Any
thoughts?
This is becoming a real concern to me especially because of how conscious
I
am now of the general dust floating around our studio. I make all my
classes wipe down all surfaces and mop all the floors, but not every
teacher does this after each class. Then there's dust lurking in lots of
corners -- uncleaned slab roller cloth and wooden bats, plastic wadded up
in the trash can with dry clay bits all over it, an opened bag of bone
ash
sitting under the wedging table -- the list could go on for days. And
after lab time it is really bad, with people doing the "not me" excuse
for
messes left everywhere. Short of becoming the janitor and cleaning up
after
everyone (or leaving my job altogether) what can I do? I've already
asked
my boss (who is not a potter) to order Monona's book, and I keep making
her
post signs reminding people to clean up, I've posted the the article from
the Laguna website on "the dangers of crystalline silica" but nothing
seems
to help. And I'm leery of pushing too hard. I seem to be the only one
with any concerns and I'm the youngest teacher there....
This is a really difficult issue for me, especially since my
apprenticeships were with really well-trained potters who kept immaculate
studios (I know because I did a lot of the cleaning work!). Is there
anyone else who has had this problem (especially at the community center
level) and dealt with it successfully?
Thanks in advance for any ideas, help or encouragement you could offer.
Julie
in VA, whose big yellow car has a solid coat of orange pollen (trees were
a
4 on the pollen meter today, ACK!) Particles, particles everywhere....
Lori C. Larsen, P.Ag.
Environmental Project Manager
PHH Environmental Ltd. and a evening and weekend
potter in Vancouver, B.C. Canada
Clark & Julie Kent on sun 9 may 99
Lori,
Thanks so much for researching this topic and sharing the information with
everyone. It was tremendously helpful to read your post and understand the
whys and wherefores of a properly fitted respirator (I have yet to go to
the NIOSH site; my computer is really old and slow, so I surf on my
sister's computer).
I hope this continuing thread doesn't bore everyone else, but I honestly
think this topic is glossed over (with a big indifferent shrug) much of the
time, especially for those of us working in the hobby atmosphere of
community centers, etc.
Frankly, I despair that our small arts facility will take any of this under
consideration. However, I feel much more confident in my understanding of
the topic and much better prepared to discuss this with the people in
charge.
Again, many thanks for your help, Lori.
Julie Kent
>----------------------------Original message----------------------------
>Long, so if you are not interested just skip ahead.
>
>I had responded directly to Julie Kent's first post about paper
>disposable filters and respirators as I my main work is with an
>environmental consulting company that specializes amongst other things in
>occupation hygiene. Julie's posts are included at the end so you can
>refresh your memory. After she posted again I realized that I was
>assuming a whole lot about respirators and dust masks and decided to get
>some straight information on the whole topic.
>
>As many people have mentioned, the dust in studios is largely from clay
>and clay contains silicon. Inhaling silicon can cause coughing,
>wheezing, decreased pulmonary function, progressive respiratory symptoms
>and eventually silicosis. It is also an eye irritant and is considered
>carcinogenic. This information is from Niosh Pocket Guide to Chemical
>Hazards available on the web at http://www.cdc.gov/niosh/npg/npgd0553
>Look up silica, crystalline (as respirable dust). That same source says
>that the time weighted recommended exposure limit is 0.05mg/cubic metre.
> More info on exactly what part of the silica is harmful, the IDHL or
>immediately dangerous to life or health, is also listed.
>
>The Niosh guide has recommendations for respirator selection. If you are
>to be exposed to 0.5mg/cubic metre (note this is 10 times the maximum
>time weighted exposure limit) you are to use a HIE (APF 10) meaning any
>air-purifying respirator with a high-efficiency particulate filter. APF
>stands for Assigned Protection Factor. APF > (Workplace Airborne
>Concentration / NIOSH Recommend Exposure Limit) If you are exposed to
>1.25 mg/cubic metre of silica dust, you should be wearing a
>PAPRHIE/SA:CF(APF 25) meaning a powered air-purifying respirator with a
>high-efficiency particulate filter operated in a continuous flow mode.
>
>The 1995 Niosh Respiratory use policy states "It is emphasized that the
>APF in the above criterion is the minimum recommended by NIOSH. The use
>of respirator types with higher APFs is preferred. Specifically, NIOSH
>recommends always selecting the respirator type with the highest APF that
>is compatible with the conditions of each particular workplace. This is
>particularly true for workplace exposures to carcinogens since there may
>be no exposure level below which there is no risk of disease. When
>respirators are used to reduce exposure to carcinogens, the risk of
>disease will decrease as respirators with higher APFs are selected. It is
>further emphasized that the use of respirators in no way eliminates the
>need to reduce ambient workplace exposures to the lowest feasible level
>through the use of process changes and engineering controls."
>http://www.cdc.gov/niosh/respuse.html
>
>How do you know what filter you should be wearing?? Good question. I
>searched the web and picked my co-workers brains for this one as now it
>becomes confusing. Like all good scientists, my co-workers said, have
>you tested the air? Of course not, us studio potters don't have the
>corporate budgets to hire a consultant firm like the one I work for. So
>we make assumptions in order to get some sort of answer. You know what
>assume means...making asses out of "u" and "me". So keeping that in
>mind, we can "safely" state that we probably are not in an atmosphere
>that exceeds more than ten times that of our acceptable time weighted
>average exposure limit of 0.05mg/cubic metre.
>
>Great now we know what we need to get a HIE(APF10) so what is that. Well
>an air purifying respirator comes in many forms. It is a device that you
>can draw air through that will filter particles and is usually powered by
>yourself by breathing in (and out). This class includes half face
>respirators, you know the soft rubber ones with two cartridges on either
>side AND includes the disposable throw away paper masks if they are rated
>properly (the ones that everyone has questions about). The new public
>health regulations 42 CFR 84 (in the USA only) state that to protect
>against dusts and mists only you must have an N (not resistant to oil)
>95, 97 or 99.97 percent efficient filter. The old ratings for filters
>used to be Part 11 code filters. Now Niosh also states "Because
>research shows that particles sized 2 micrometers or smaller can
>penetrate some DM [dust & mist respirator (APF=5)]and DFM [dust & mist
>respirator with a full facepiece (APF=10)] filters, these Part 11 filters
>should be used only when the mass median aerodynamic diameter (MMAD) is
>known to be greater than 2 micrometers [NIOSH 1995]. If this diameter is
>less than 2 micrometers or is unknown, a Part 11 HEPA filter or any Part
>84 filter should be used. In Canada, according to my co-workers, only the
>half face respirators with HEPA cartridges are adequate.
>
>What is the difference between the two?
>
>Well the rubber half face respirators with high efficiency filters have
>an efficiency rating of 99.97 percent when using filters are commonly
>known as HEPA - High efficiency filters for aerosol. Yes a HEPA filter
>qualifies as a HIE filter. A half face respirator can be fit tested to
>ensure that it is fitting properly and that all the air that you breath
>is going through those filters. This respirator IS more effective than
>the dust masks because it can create a seal on your face BUT it MUST be
>fitted properly.
>
>The dust masks that Julie mentioned the 3M 8210 N95 meets NIOSH 42 CFR 84
>N95 requirements. You can look at this mask at
>http://www.plasticsnet.com/Scripts/ProductCat/ProductDisplay.cfm?ReqSeller
>Id=0F51C504067411D1B70E0060970EA55A&ReqCoHandle=imscompany&ReqProductId=99
>465F90C02F11D2BA300060970EA287&ReqHierId=A2FF7A53BF5811D2BA300060970EA287
>
>
>(sorry for the long URL, just click on it) This mask will filter 95
>percent of the dust particulates to 0.3um MMAD (mass median aerodynamic
>diameter) Sodium Chloride Particle challenge. Sounds good right? Not
>exactly. This mask will filter all air that goes through the filter at
>that rate. What about the air that escapes in around the sides??? I
>sort of figured out that the air that escapes in from the sides is just
>one of the reasons why it is rated at 95 percent. My co-worker
>interpreted even differently than what I gleaned from the online NIOSH
>and OSHA articles,. He thought that mask would only have a 95 percent
>efficiency rating if was fitted perfectly and there is NO WAY to test to
>make sure that it fits well. Short of crazy gluing it on to your face
>(which would hurt when you took it off) there is no way to ensure a
>perfect fit. Well you may be able to fit test it using irritant smoke
>but chances are that you won't have access to this.
>
>So there should be a big "ah ha!" here. Do I see light bulbs going on
>every where? My it IS bright! But I hear you say, NIOSH just say
>particulate filters and don't specify which exactly to use. Well they do
>admit that the minimum for use should be a 95 percent efficient filter
>but readily admit that such filters should be tested to ensure that they
>fit. So in reality, the best respirator is the cartridge ones that you
>can at least do positive and negative air pressure checks yourself and
>can then get an irritant smoke test. (the banana oil test is only for
>filters with organic cartridges!)
>
>The cost issue is bogus. The dust mask is intended as a one use, being
>one eight hour shift. If you use it less than that, you could probably
>use it a couple of times before throwing it out. You should keep it
>clean and in its original shape. Lets say you are using these masks and
>go through one per week. That $3 times 52 weeks which is $156. For a
>half face respirator you pay an initial $35-$50 for the mask itself then
>the HEPA filters cost you about $7 to $10 a pair and the rule of thumb is
>to replace them every six months sooooo.. lets see here about $70 for a
>half face respirator for a year. MUCH less, MUCH more protection if
>properly fitted and fit tested. Your supplier should be able to get you
>fit tested for the cost of purchasing the filter. If not go elsewhere.
>
>About that 4 percent comment in the article. I don't know about you, but
>4 % may just mean the difference from feeling healthy and being sick.
> Again your choice.
>
>Fit testing for half face respirators has been covered adequately in
>dribs and drabs over the last few days. I hope that all this helps you
>make decisions. Now I am going to find that article in Pottery Making
>Industry and email this to the author of it.
>
>JULIE'S FIRST POST
>
>Subject: Re: Small dust masks
>
> ----------------------------Original message----------------------------
>I wanted to address this whole dust mask issue because I have had an
>offer
>from a relative (who works in light industry) to get me a good dust mask
>at
>cost. Of course, he needs to know what size I am. If I go to Home Depot
>and try on whatever they have on the shelf will narrowing it down to
>small,
>medium or large be sufficient? Or does mask size vary enough from brand
>to
>brand to make this kind of guesswork useless?
>
>And while we're on the subject of dust masks, I was very confused by the
>article "Respirators for Potters" in this spring's Pottery Making
>Illustrated by Jeff Zamek which listed a paper dust mask as a "first
>choice....for protection against airborne particles found in the pottery
>studio." Did anyone else stop short at reading that? I was under the
>impression that it is very important to have that respirator seal against
>your face, otherwise you are breathing in particles around the sides
>anyway. The article states that there is a mere difference of 4 percent
>(the paper mask filtering 95 percent of particles, and the highest rated
>NIOSH particle respirator filtering 99.97 percent)
>
>Now, I have been grumbling on and off about the aforementioned disposable
>paper dust masks that are in use at our community art center -- mostly
>because it was recommended we re-use them by putting them in a plastic
>bag
>(!). I refused and toss mine out after one use (cleaning shelves or
>grinding ware outside). However, I also refuse to mix glazes inside
>unless
>they buy me my own particle respirator, because I just feel like those
>little flimsy paper things are not enough to stand between me and major
>lung problems (as an ex-smoker and an ex-asthma sufferer I try to be
>extra
>careful). Am I wrong to take this position?
>
>I also shuddered at the opening line in the article where he mentions
>sweeping his studio -- who does that? I was under the impression that
>all
>studio cleaning should be wet cleaning.
>
>Interested in other (older and wiser) people's responses to this
>article....
>
>Julie Kent
>
>JULIE'S SECOND POST
>
>Subject: Dust masks, cleanliness & other safety concerns
>
> ----------------------------Original message----------------------------
>Thanks to everyone who has replied to my post on dust masks/respirators.
> I
>still am wondering if I *can* get an ok seal on the 3M 8210 that is used
>in
>our community studio. It's going to take me a while to do my homework,
>find my own respirator and get it fitted properly (and thanks for the
>suggestions).
>
>Meanwhile, I still have to go to work at the clay center and do my job.
>And the most immediate concern is not the filter itself (which has a 95%
>efficiency rating, which isn't bad), but the fit of the filter on my
>face.
>So the question becomes, how can I be certain that the filter is doing
>it's
>job while I'm bending over and contorting myself to clean those shelves?
>
>Although the ideas of smelling banana oil or a saccharine hood are great
>for companies that test this kind of thing regularly, what might be a
>practical way of testing the seal myself? I don't know of any
>manual/textbook that covers this -- it goes down in the "just figure it
>out" section that so much of pottery is relegated to.... What if I light
>a
>candle, blow it out, then put on the mask and see if I can smell the
>smoke?
>Or perhaps some airborne confectioner's sugar might be a better test
>because of the fine particles that I would be able to taste? Any
>thoughts?
>
>This is becoming a real concern to me especially because of how conscious
>I
>am now of the general dust floating around our studio. I make all my
>classes wipe down all surfaces and mop all the floors, but not every
>teacher does this after each class. Then there's dust lurking in lots of
>corners -- uncleaned slab roller cloth and wooden bats, plastic wadded up
>in the trash can with dry clay bits all over it, an opened bag of bone
>ash
>sitting under the wedging table -- the list could go on for days. And
>after lab time it is really bad, with people doing the "not me" excuse
>for
>messes left everywhere. Short of becoming the janitor and cleaning up
>after
>everyone (or leaving my job altogether) what can I do? I've already
>asked
>my boss (who is not a potter) to order Monona's book, and I keep making
>her
>post signs reminding people to clean up, I've posted the the article from
>the Laguna website on "the dangers of crystalline silica" but nothing
>seems
>to help. And I'm leery of pushing too hard. I seem to be the only one
>with any concerns and I'm the youngest teacher there....
>
>This is a really difficult issue for me, especially since my
>apprenticeships were with really well-trained potters who kept immaculate
>studios (I know because I did a lot of the cleaning work!). Is there
>anyone else who has had this problem (especially at the community center
>level) and dealt with it successfully?
>
>Thanks in advance for any ideas, help or encouragement you could offer.
>
>Julie
>in VA, whose big yellow car has a solid coat of orange pollen (trees were
>a
>4 on the pollen meter today, ACK!) Particles, particles everywhere....
>
>
>
>
>Lori C. Larsen, P.Ag.
>Environmental Project Manager
>PHH Environmental Ltd. and a evening and weekend
>potter in Vancouver, B.C. Canada
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