search  current discussion  categories  kilns & firing - raku 

raku sickness

updated sun 30 jun 96

 

Julie Elver on fri 7 jun 96

When raku firing outdoors in my high school class recently, two of
my students who were my primary helpers that day became sick with a
cough and one got a rash on one side of his body. I have done
several raku firings with students without incident. I'm wondering
if any of you clayart people have experienced anything like this or
know a possible cause.The glazes are copper and ferrofrit 3134
based among other things. Also, I've noticed that a yellow gas
emerges with the smoke. Is this sulfur? What other gases besides CO
and CO2 are present in that smoke?


Julie Reimer Elver
Antioch Community High School
1133 S. Main Street
Antioch IL 60002

1
c

Erin Hayes on sat 8 jun 96

I sometimes have respiratory problems after marathon raku sessions with
my classes. I don't know any other reason than breathing disguting smoke
fumes, but I would guess that the garbage produced from inks and papers,
or whatever combustibles you are using could very well cause problems.
My lung troubles get a little worse every time, so I am extremely careful
to use as little combustible as possible to acheive the effect I want and
also to stand far away from the bins when they are opened to let the
exhale before I stick my head down in there. ICK!

=============================================================================
Erin Hayes, Art and Humanities Instructor Office: (509) 575-2418
Yakima Valley Community College E-mail: ehayes@ctc.edu
PO Box 1647
Yakima, WA 98907 "Clay is Good."
=============================================================================

laurenb on sat 8 jun 96

Julie Elver wrote:
>
> ----------------------------Original message----------------------------
> When raku firing outdoors in my high school class recently, two of
> my students who were my primary helpers that day became sick with a
> cough and one got a rash on one side of his body. I've noticed that a yellow
> emerges with the smoke. Is this sulfur? What other gases besides CO
> and CO2 are present in that smoke?
>
> Julie Reimer Elver
>If there was any salt present you can produce Chlorine a highly toxic yellow ga
particicles floating in hot air.) Inhalation of Chlorine or other gases,
smokes and fumes, can be seriously hazardous to your health. Causing for
example chemical pneumonia, immune reactions, rashes, irritated mucous
membranes, diarrehea, naseau, vomiting, cancer, brain damage, etc.

Basically don't breath the smoke, dust, or fumes, that are an integral
part of pottery. Note that if you smoke it will increase the risk.

dannon@ns1.koyote.com on sat 8 jun 96

>----------------------------Original message----------------------------
>I sometimes have respiratory problems after marathon raku sessions with
>
>also to stand far away from the bins when they are opened to let the
>exhale before I stick my head down in there. ICK!
>
>==============================================================================
>Erin Hayes, Art and Humanities Instructor Office: (509) 575-2418

>
>One hates to belabor the obvious, but a)wear a decent mask; b)if you know
the smoke bothers you, and/or you have lung problems, WEAR A MASK!!

Dannon Rhudy

Robert Wilt on sun 9 jun 96

I'm not a medical expert, but I do a lot of raku, so I have some
opinions.

First, let's assume it was a normal firing you had that day. In that
case the cough is understandable. Some people are more sensitive than
others to smoke and chemicals; I find myself more sensitive on different
days. If your helper accidentally got a too-big whiff of smoke, it
could have set off the cough.
The rash probably has something to do with that individual's reaction
to heat, stress, and/or smoke. I've only seen a rash on rakuers who got
overheated. Definitely ask a doctor, though.
If you are using glazes heavy in copper, you also have to watch out
for copper fumes. I don't know much about the issue, though, so I'll let
someone else tackle it.

Possibly something unusual was going on that day. Do you use
sawdust, newspaper, leaves, straw, or ...? Sawdust especially can
vary in composition, and different sawdusts produce different levels
of secondary chemicals in the smoke (I have not researched what they
are, though - it would probably take an organic chemist to understand
it well.) Impurities in the reduction material - especially stray bits
of plastic - can result in some really bad fumes.
Bad fumes can also come from plastic inside the clay, or from unusual
materials painted on with or instead of the glazes (like paints). This
doesn't happen often, but maybe someone was experimenting? Those sorts
of fumes generally come from the kiln, though.

As for the yellow smoke... yellow smoke = danger. In general, yellow
smoke means half-burnt hydrocarbons. The process of burning works something
like this: wood/paper heats, cellulose breaks down into smaller organic
chains which escape in gaseous form, these combine with oxygen in the air
to produce CO2, H2O, and more heat. Self-sustaining. However, two things
mess up this neat cycle. First, impurities in the wood - non-hydrocarbons -
can volatize but not burn, or react in different ways, meaning your smoke
might be full of nitrates, sulfates, and whatever. Second, since you are
creating a reducing atmosphere in the can, there is not enough oxygen to
burn all the gaseous hydrocarbons. These escape from the can as yellowish
smoke (I'm not sure why it's yellow). These gases are just looking for an
opportunity to combine with some oxygen, and if they ignite before they
disperse sufficiently, could explode in a fireball.
Before you panic - it's not usually a very big fireball. You basically
just have to keep out of the way. The danger is that if you pile multiple
pieces into cans, the first pieces start the combustion and production of
yellow smoke, especially if you put the lid on the can. Then you have to
reopen the can to put more pieces in, so when you take off the lid the air
hits the smoke and Boom (or Whoosh). It sometimes happens and sometimes
does not, but you have to be careful, and always remove lids from
smoking cans by standing back and sliding them toward you.
The yellow smoke, by the way, is also much more obnoxious than the
white smoke if you breath it (even after it disperses enough to not
explode).
To minimize smoke production and inhalation:
- one piece per can
- seal lids tightly - use wet towels or newspaper if necessary
- wear a mask with smoke-blocking filters
Plastic goggles can also help keep the smoke out of your eyes.

hope this helped
bob

C. van Riemsdijk on tue 11 jun 96

Yes, always wear a mask, but....
Make sure that the filters used in the mask are suitable for organic fumes, not
just dust.
These filters should be "added" to the mask.
Filters and masks should be available from your local pottery supply shop.
Take notice that these carbon filters have a limited shelf life. Check for
"freshness"
It always amazes me that people are so cavalier about their own and other
peoples health.
Take care.
Carolien,
Haarlem, the Netherlands.

Playclay@aol.com on tue 11 jun 96

I haven't seen anyone else say this, so I will:

Don't EVER use sawdust from pressure-treated wood for either raku reduction
or a sawdust firing.

I don't remember the chemical used in the wood; but it's very toxic. A
potter I knew said that a friend of hers almost died from the smoke during a
raku firing.

Dave Hedblom on tue 11 jun 96

>----------------------------Original message----------------------------
>When raku firing outdoors in my high school class recently, two of
>my students who were my primary helpers that day became sick with a
>cough and one got a rash on one side of his body..........



Julie,
You might want to check out the reducing agent you used. My wife was
once helped during a grass fire by her home. There was poison ivy in the
grass and she didn't protect herself properly. She ended up in the hospital
from the smoke. Covered from head to foot with rash. It was also down her
throat and in her lungs.



Dave Hedblom
cobalt@winternet.com

Dave Eitel on thu 13 jun 96

>----------------------------Original message----------------------------
>I haven't seen anyone else say this, so I will:
>
>Don't EVER use sawdust from pressure-treated wood for either raku reduction
>or a sawdust firing.
>
>I don't remember the chemical used in the wood; but it's very toxic. A
>potter I knew said that a friend of hers almost died from the smoke during a
>raku firing.

An article in the Milwaukee Journal/Sentinel home section said, "Most
pressure treated wood contains chromated copper arsenate, or CCA, a
compound that includes arsenic....Never dispose of treated-wood scraps by
burning them--the vapors are toxic...."

Later...Dave


Dave Eitel
Cedar Creek Pottery
Cedarburg, WI
daveitel@execpc.com
http://www.digivis.com/CedarCreek/home.html

james & becca sydnor on thu 13 jun 96

Robert Wilt wrote:
>
> ----------------------------Original message----------------------------
> I'm not a medical expert, but I do a lot of raku, so I have some
> opinions.
>
> First, let's assume it was a normal firing you had that day. In that
> case the cough is understandable. Some people are more sensitive than
> others to smoke and chemicals; I find myself more sensitive on different
> days. If your helper accidentally got a too-big whiff of smoke, it
> could have set off the cough.
> The rash probably has something to do with that individual's reaction
> to heat, stress, and/or smoke. I've only seen a rash on rakuers who got
> overheated. Definitely ask a doctor, though.
> If you are using glazes heavy in copper, you also have to watch out
> for copper fumes. I don't know much about the issue, though, so I'll let
> someone else tackle it.
>
> Possibly something unusual was going on that day. Do you use
> sawdust, newspaper, leaves, straw, or ...? Sawdust especially can
> vary in composition, and different sawdusts produce different levels
> of secondary chemicals in the smoke (I have not researched what they
> are, though - it would probably take an organic chemist to understand
> it well.) Impurities in the reduction material - especially stray bits
> of plastic - can result in some really bad fumes.
> Bad fumes can also come from plastic inside the clay, or from unusual
> materials painted on with or instead of the glazes (like paints). This
> doesn't happen often, but maybe someone was experimenting? Those sorts
> of fumes generally come from the kiln, though.
>
> As for the yellow smoke... yellow smoke = danger. In general, yellow
> smoke means half-burnt hydrocarbons. The process of burning works something
> like this: wood/paper heats, cellulose breaks down into smaller organic
> chains which escape in gaseous form, these combine with oxygen in the air
> to produce CO2, H2O, and more heat. Self-sustaining. However, two things
> mess up this neat cycle. First, impurities in the wood - non-hydrocarbons -
> can volatize but not burn, or react in different ways, meaning your smoke
> might be full of nitrates, sulfates, and whatever. Second, since you are
> creating a reducing atmosphere in the can, there is not enough oxygen to
> burn all the gaseous hydrocarbons. These escape from the can as yellowish
> smoke (I'm not sure why it's yellow). These gases are just looking for an
> opportunity to combine with some oxygen, and if they ignite before they
> disperse sufficiently, could explode in a fireball.
> Before you panic - it's not usually a very big fireball. You basically
> just have to keep out of the way. The danger is that if you pile multiple
> pieces into cans, the first pieces start the combustion and production of
> yellow smoke, especially if you put the lid on the can. Then you have to
> reopen the can to put more pieces in, so when you take off the lid the air
> hits the smoke and Boom (or Whoosh). It sometimes happens and sometimes
> does not, but you have to be careful, and always remove lids from
> smoking cans by standing back and sliding them toward you.
> The yellow smoke, by the way, is also much more obnoxious than the
> white smoke if you breath it (even after it disperses enough to not
> explode).
> To minimize smoke production and inhalation:
> - one piece per can
> - seal lids tightly - use wet towels or newspaper if necessary
> - wear a mask with smoke-blocking filters
> Plastic goggles can also help keep the smoke out of your eyes.
>
> hope this helped
> bob
I' new to posting on clay art, so I hope this works. One of the agents
in pressure treated lumber is arsenic and yes there is enough to harm
someone. The literature on most pressure treated lumber,which you are
usually not given, suggests that it is unsafe to handle for extended
periods of time (makes you wonder about that deck?). The information
given with the wood also expresses extreme caution when burning that
material. To be safe use only untreated organic materials or newspaper
which uses soy base inks.
Jim S

Tom Buck on fri 14 jun 96

Dave: Here in Ontario the wood-treating plants use penta chloro phenol (a
benzene ring with 5 chlorine atoms and one hydroxyl group attached). This
material is hell on wheels toxic. A real no-no for burning. I know it
used elsewhere too. Tom.Buck@freenet.hamilton.on.ca