by Stan
Wolfersberger
Introduction:
Making glass beads can be a very rewarding activity.
Beadmaking does entail using equipment and materials
which need to be handled properly so that your
experience is as safe as possible. Keep in mind that
you, the beadmaker, need to take responsibility for
practicing safe behavior. You are the one who knows
all the details of your set-up - what kind of torch
you use, what kind of fuel gas, the size of your
studio, your local and state regulations, building
codes, and so on. The guidelines that follow will be
very helpful, but understand that there may be
individual circumstances where you need to do more
research to ensure your operation is safe. A list of
suggested sources for additional safety information
has therefore been included.
To make glass beads, you need a source of heat
sufficiently hot that it can melt glass. Torches
using a variety of gases are by far the system in
greatest use, since they are fairly simple, compact,
and relatively inexpensive. Beginner kits often
employ a fuel gas mixture known as “MAPP” gas (MAPPTM
is a trademarked mixture of methylacetylene,
propadiene, and other hydrocarbons which has been
stabilized1). This burns sufficiently hot in air
(which is about 21% oxygen1) that a separate tank of
oxygen is not needed. Most beadmakers advance to
torches that use propane and oxygen; a minority of
folks use natural gas and oxygen. Torches and
associated materials constitute the source of the
most significant safety issues associated with glass
beadmaking.
Risk is an interesting concept. Most people have
no fear of jumping in their car and driving to work,
shopping, or wherever. It is an activity which is
very common, but it is also one in which we have a
great degree of control. Yet being in an automobile
is a much higher-risk activity than many other
things people fear, statistically. As you become
accustomed to doing something, the caution you may
have felt initially begins to wear off. This has
many parallels to beadmaking. Just as in driving,
you may not always have an accident when you engage
in unsafe behavior. But sometimes, the unsafe
behavior can lead to terrible consequences. I have
used the nature of the consequences to rank the
beadmaking safety issues in importance, starting
with potentially catastrophic events and ending up
with the merely irritating.
Highest Risk Safety Issues:
Fuel Gases
Whether you use MAPPTM gas, propane, or natural gas,
you are dealing with highly flammable and
potentially explosive substances. Proper handling of
your fuel gas is therefore absolutely essential.
Fuel gas tanks should be transported in a vertical
position (valve up) and be secured. If possible,
keep the tank out of the passenger compartment of
your vehicle during transportation.2
Avoiding leaks in your fuel gas set-up is
relatively easy. Visually inspect all connections to
be sure that threads, nuts, and sealing surfaces are
not nicked or damaged.
Components are very inexpensive and should be
replaced if not in good condition. After making
connections, an appropriate leak detecting solution
can be brushed onto each junction. The solution will
normally make bubbles if gas is escaping at any
point.
Retighten the connection and then re-check. TeflonTM
tape can be used on threads to help seal
connections. You can also check entire hoses by
immersing in a bucket of water and looking for
bubbles. An odorant is added to most fuel gases, but
since people have widely different sensitivities, it
is better to not rely on your sense of smell to
detect leaks. If your gas delivery kit did not come
with flashback arrestors, these are relatively
inexpensive additions which should be added to both
gas lines.
Propane and MAPPTM are liquids when compressed, so
the tank pressure is partially dictated by the
equilibrium between gas and liquid. The safety
consequence is that the tank pressure is not
particularly high (125 pounds per square inch gauge,
psig, is typical for propane) so the potential
energy from pressure is of less concern than a
high-pressure compressed gas like oxygen. In many
locations the fuel gas may not be propane per se,
but a mixture known as LPG (Liquefied Petroleum Gas,
which is typically a mixture of propane, butanes,
and other hydrocarbons1). LPG has very similar flame
and other properties to propane alone, and therefore
for the rest of this discussion both LPG and propane
will be collectively referred to as propane.
Most portable fuel gas tanks, especially the
larger ones, will have pressure relief valves. These
devices are set to release the contents if the
pressure at the relief valve exceeds a certain
value. While this would prevent the tank from
exploding due to excessive pressure, it also
presents a risk in itself since the contents are
highly flammable. This is the basis for recommending
that if at all possible, your fuel gas should be
stored outside, especially if you use a fairly large
tank. Some jurisdictions prohibit indoor storage or
use of fuel tanks. Avoid exposure of your tank to
rapid fluctuations in temperature which could cause
a pressure build-up - for example, getting your
propane tank filled on a cold winter day, bringing
it home, then placing in a hot location. Most tank
manufacturers recommend that tanks not be stored in
direct sunlight for the same reason.
The specifications required for propane tanks in the
4 - 40 pound range were changed in 1998. Tanks made
after September 1998 were required to have an
“Overfilling Protection Device”, or OPD. Cylinders
which meet the OPD requirement “have a unique,
trilobular handwheel”.3 You may not be able to get
your old tank (without an OPD) refilled after April
1, 2002. Some states or jurisdictions have not
adopted the 1998 version of NFPA 58, and/or are not
enforcing OPD usage, so in these areas you may be
able to use your old tanks for a bit longer. Even
though I have 3 older model tanks, I will probably
get new ones since an OPD device protects me from a
potentially dangerous error by the person filling
the tank.
Finally, keep in mind the consequences of
equipment failure. These can range from a small
release of fuel (cracked hose) up to the entire fuel
tank contents venting (regulator failure, pressure
relief valve). If your whole tank vents, and there
is a spark or flame nearby, the consequences can
truly be terrible.4 One of the first rules to keep
in mind is that “bigger is not necessarily better”.
Most of the time larger tanks end up being less
expensive in terms of fuel cost, but in the event of
a failure the consequences can be far worse. Arrange
your studio so that you have a clear exit in case of
emergency, and keep a fire extinguisher by the exit
for use on small fires.
Oxygen
A common misconception is that oxygen is
“flammable”. It is not. It does, however, greatly
accelerate combustion of many other materials. Pure
oxygen combined with fuel gas results in higher
flame temperatures than air alone (recall air only
has 21% oxygen), and this is why it is used in
conjunction with propane and natural gas for
beadmaking. The ability of oxygen to accelerate
combustion, and the form in which it is usually
obtained (compressed gas cylinders) are the areas to
be aware of from a safety standpoint.
Special equipment and precautions are required for
oxygen. The gas regulator must be of materials
suitable for contact with oxygen. Never use a
regulator which has been used for other applications
or gases. Do not allow the cylinder outlet or the
valve area to become contaminated with any type of
organic material, such as oil or grease. Contact of
these materials with high-pressure oxygen can result
in fire or explosion5.
Oxygen can be supplied in both steel and aluminum
gas cylinders in various sizes. These are all under
high pressure, and thus the cylinders must be
handled with great respect. Compressed gas cylinders
can literally become “rockets” if the valve breaks
off.
Therefore, every tank comes with a threaded cap to
protect the cylinder valve. Be sure to inspect the
cap for tightness prior to attempting to load or
move the cylinder. (Note, some oxygen suppliers will
deliver tanks to your home or studio; however,
others may not because of insurance restrictions,
company policy, etc. Therefore I cover the issues
involved with picking up cylinders at a supplier, as
well as for those fortunate enough to get their
oxygen delivered).
If you pick up your own oxygen tanks, be sure you
get a tank size which can be safely handled. While a
larger tank provides a lower cost per amount of
oxygen, most of the larger tanks are very difficult
for one person to handle. If you have a studio which
is not on the ground floor, have steps you need to
ascend, and so on, it may be very difficult to move
the tanks to your studio. Also keep in mind the
vehicle that you will be picking up your tanks in -
can you use proper lifting techniques to avoid
straining your back? You should also be able to
secure the cylinder or cylinders in the vehicle to
prevent damage to them or your vehicle during
transportation. Oxygen cylinders can be transported
either horizontally or vertically, again taking care
that the cylinder cap is on securely. Safety shoes
with steel toes are highly recommended whenever you
move cylinders.
At your home or studio, cylinders should be
stored upright and secured. Cylinder clamps are
available from suppliers, or the cylinders can be
retained by a chain. As with fuel tanks, it is best
to avoid a location in direct sunlight or subject to
temperature extremes. Carts specifically for gas
cylinders are available if you must move a tank or
tanks some distance to your storage location. Of
course, if you keep your oxygen tank in your studio,
it should also be secured properly.
Connecting your regulator to a “fresh” oxygen
tank and checking for leaks requires a slightly
different approach than for your fuel tank. All of
these steps should be carefully adhered to. First,
point the outlet to the oxygen tank away from you.
Then gently “crack” the valve (open slightly then
close) to blow any dust or particulate out of the
regulator seating area. Taking care to avoid getting
any oil, grease, or dirt onto the threads or
regulator, install the regulator with a wrench
securely. The regulator should be dialed out so that
there will be no oxygen released (it should have
been bled of pressure
and set to “no pressure” setting when taking off the
old tank).
Keeping your face away from the tank and
regulator, gently open the tank valve slightly to
pressurize the regulator. Close the tank valve. Note
the high pressure reading on your regulator, which
differs depending upon your tank size but will
typically be in the range of 2000 psig or greater
for a full tank. Allow several minutes to elapse.
Then note the regulator reading again. If it has
decreased significantly, this indicates you have a
leak in your regulator
connection. This may require you to tighten the
connection further, or sometimes to change the
orientation of the regulator seating area and
retighten. Repeat the procedure of pressurizing the
regulator, noting the reading, and checking several
minutes later.
In rare cases the tank fitting may be damaged and
should be returned to the vendor for replacement
with a different tank. This procedure is highly
recommended for the oxygen regulator connection to
ensure contamination of the high-pressure area with
soap or other organics does not take place.
Oxygen-safe leak detecting solutions are available,
and are a safe alternative to checking the
regulator-tank connection, and hoses and connections
downstream from the regulator.6 When using your
oxygen, always open the tank valve
gently and slowly. Then proceed to open the valve
fully, as otherwise the valve may leak some oxygen
during use5,7. TeflonTM tape can be used for threads
to help seal lowpressure connections.
Fuel gas and oxygen suppliers will provide you
with a Manufacturer’s Safety Data Sheet (MSDS) upon
request. These provide additional safety information
on the nature of the specific hazards. Many of the
compressed gas suppliers (Praxair, Matheson, Air
Products) also have safety information and/or MSDSs
available on their websites.
Oxygen generators are gaining increased attention
as alternatives to compressed oxygen tanks. These
are often used pieces of equipment, having been
first utilized for medical applications. From a
safety standpoint, use of an oxygen generator
alleviates several of the potential safety concerns
of tanks: Oxygen is never at high pressure; one need
not transport tanks; and one need not handle the
heavy cylinders. Be sure to ask about the electrical
power consumption, cost of consumables, and so on to
see if this option is better than compressed oxygen
tanks for you.
Lastly, a word on the proper order for lighting your
torch is appropriate. Most books on lampworking
teach the acronym “POOP”, for Propane first, then
Oxygen (when lighting the torch); and Oxygen first,
then Propane when shutting the torch off8,9,10.
Always read the information provided by the
manufacturer of your torch on the proper procedure
to follow. At the end of the day, shut off your
tanks at the tank valve, and bleed any pressure from
the regulator and hoses. Leave your ventilation on
for a short time after your session to be sure all
traces of bled fuel gas and combustion by-products
are removed. For the interested reader, the book by
Kervin has a very good discussion of equipment and
gases used in beadmaking.9
Ventilation
Great, you now have your fuel and oxidizer all
hooked up to your torch safely. From the very moment
you light your torch, you are now creating
combustion by-products which must be removed by
ventilation.
The combustion gases released when your torch is
burning include: Carbon dioxide, water, nitrogen
oxide, nitrogen dioxide, and carbon monoxide, as
well as trace amounts of unburned fuel and other
contaminants. One of the most popular “urban
legends” of beadmaking is that carbon monoxide is
the principle agent to be worried about. However, in
general this is not supported by actual
measurements. The chief “bad actors” are the
nitrogen oxides, especially nitrogen dioxide, which
are produced by any high-temperature flame.11,12 In
addition to producing the familiar “torch smell”,
nitrogen dioxide is a severe respiratory irritant
with a very low acceptable air concentration.13
Your ventilation system should be actively
pulling fumes away from the place they are generated
- at your torch. Additionally, fresh air should be
entering your beading area so that uncontaminated
air is in your breathing zone. I prefer a push-pull
fan arrangement to accomplish both: Air is exhausted
from the room with one fan, while a second fan is
used to push air toward the torch area. To make this
method work, your exhaust fan should be located
fairly close to the torch, and the exhaust directed
or ducted outdoors. It is much easier to use a fan
to push air a long distance at a reasonable velocity
than it is to pull it, thus the need for the exhaust
fan to be fairly close to the torch.14
It is usually possible to orient your workbench
and torch placement in a room so that you can
maximize ventilation. If you live in a climate where
your house is closed up, be sure to open a window in
another room to allow make-up air to enter the
house. This is
especially important in cases such as a basement
studio - if you do not provide a means for clean
make-up air to enter, the depressurization of your
house by your exhaust fan
will pull air through any crack or opening. And one
of the largest openings in your home may be a
furnace or hot water heater flue, or fireplace
chimney. Combustion gases that should be leaving
your house may now be pulled into it, leading to the
potential for issues such as build-up of carbon
monoxide.
A great variety of ventilation solutions are
possible depending upon the size and layout of your
studio, number of windows and doors, and so on. The
amount of exhaust air you need will be very
dependent upon these factors. Research on the
recommended exhaust needed for analytical
instruments using high-temperature flames and
plasmas found a range of 250-350 cubic feet per
minute (cfm). Based on differences between the
orientation of torches, size of hoods, and so on,
the middle of this range (300 cfm) was recommended
as the minimum for ventilating a beadmaking torch.15
If you decide to use a hood over or behind your
torch, the hood dimensions (face area), number of
bends and constrictions, and the duct size you use
are critical parameters which may dictate more
exhaust airflow is needed.15,16
“Another consideration is the velocity of the stream
of combustion products from the torch itself. The
torch gasses are under pressure, are directed
through narrow nozzles and are ignited outside the
torch. The resultant stream has quite a high
velocity and may
exceed the velocity of the airflow in the capture
zone of your ventilation system. This will allow the
bulk of the combustion products to escape the
ventilation system and contaminate the ambient air
in your working space. Depending on the placement of
your torch and your exhaust system, you may need to
install a baffle that interrupts the stream from the
torch and allows it to be captured by the exhaust
system or direct an auxiliary stream of air that
redirects the torch stream directly into the capture
zone of the exhaust system.”
You can test your set-up by placing a source of
smoke (such as a piece of smoldering paper, incense
cone, or a cigarette) near the torch. Do this with
the torch operating. Watch to see whether the smoke
is drawn away from your breathing zone by the
exhaust fan. Adjust fan placement, fan speed, and
your workstation layout as needed to achieve the
best ventilation possible. Pay attention to other
clues, such as the presence of odors due to nitrogen
oxides or the odorant in the fuel gas. Any problems
with eye, nose, or throat irritation may indicate
that your ventilation system still needs
improvement.
A final comment is in order on emissions and
oxygen generators. Oxygen generators typically
produce lower purity oxygen than that delivered in
compressed gas tanks. As the balance of the gas
being delivered to the torch by the generator is
very likely to be nitrogen, there may be higher
levels of nitrogen oxide emissions from a torch
using an oxygen generator. Keep this in mind if you
switch from an oxygen tank to a generator and notice
any changes in irritation, odors, and so on.
Eye Protection
Protecting your eyes is essential, as beadmaking
presents several different hazards. The primary
reason for including eye protection in the “high
risk” category is the potential for shards of glass
or hot fragments to be released from glass when it
“thermal shocks” due to over-rapid heating in the
torch. These pieces can fly a considerable distance,
and
represent an acute hazard.17
Other hazards to the eyes are of a more chronic
nature, and are due to the radiation emitted by
glass heated in a torch. Most beadmakers use
soda-lime glasses, commonly called “Moretti”, “Effetre”,
“Czech” and so on. These glasses melt at
comparatively low flame temperatures, meaning less
radiation is emitted than higher-melting glasses,
such as borosilicate. Most of the published
literature on radiation hazards from glass making
concentrates on infrared (IR) radiation.17,18,19
Soda lime glasses also produce a bright yellow glow
when heated, the so-called “sodium flare” in the
visible portion of the radiation spectrum.17,20
Eyeglasses should be worn which are protective of
the IR radiation (IR reducing glasses with ANSI
Shade 2.0 or equivalent). Many beadmakers prefer to
wear lenses designed for beadmaking which also
filter out the “sodium flare”, although this is not
necessary for health reasons, but because they can
see their work more clearly in the torch.
The size of the bead is one factor in how much IR
radiation is emitted (larger glass beads emit more
IR than smaller glass beads when hot). Other sources
of IR radiation may be much more significant than
the bead/torch combination. These sources include
the heating devices used, especially kilns and glory
holes. The highest IR exposure found during the
NIOSH work at Corning was from placing an article in
a kiln. You can greatly decrease your exposure by
increasing the distance between you and the source
of
radiation, since intensity falls off as the inverse
square of distance.21 For example, if you have an
exposure of “1” in arbitrary units of intensity at a
distance of 1 foot, then if you move to a distance
of 2 feet, your exposure will be cut to about 1/22,
or one-fourth the intensity. Thus, substituting long
tongs for short tongs will keep you further away
from the IR given off by a kiln. Even room lighting
can be a source of radiation, for example halogen
work lights, but the levels are generally low.
Glasses are available from several manufacturers,
and can be ordered with prescriptions for vision
correction. There are a variety of protective
lenses, with different levels of attenuation for
different glass activities.22 An alternative my wife
prefers is to wear her glasses for correcting
farsightedness, paired with a beadmaking visor which
has a filter for IR and sodium flare, and also
provides better side protection against flying
shards.
There is very little evidence of any kind of
ultraviolet (UV) radiation hazard from glass
beadmaking. This includes recent investigations by
the National Institute of Occupational Safety and
Health (NIOSH) as part of an SGB initiative.17, 23
Measured UV levels were found to be well below
recommended exposure standards. Most common
materials used in protective glasses absorb UV
radiation, so even if there were slight UV emissions
from some unusual operations, the glasses and visors
in general use would likely provide adequate
protection for the beadmaker. The books by Kervin 9
and Dunham 10 both include extensive discussion of
eye protection from a lampworker’s perspective in
their sections on Safety. For operations which
produce intense radiation, the American Welding
Society website in “Recommended Reading” is a good
source of
information.
Etching Solutions and Cremes
While generally not used by beginners, many
beadmakers like the appearance of etched beads.
Available chemical agents typically rely on the
ability of fluoride to solubilize silica, the main
oxide present in glass. The fluoride in commercial
etching agents is usually in the form of either
dilute hydrofluoric acid or ammonium bifluoride.
Both of these materials can readily penetrate the
skin, and cause damage even as dilute solutions.
Fluoride burns have very poor warning properties,
and the solutions can penetrate deep into the body
causing severe injury. Eye exposure can have the
same devastating effects.
Always wear protective gloves and eye protection
when handling etching agents. Keep these materials
in secured storage so that children and pets cannot
gain access to them. Be sure that containers used
for etching beads are never used for eating or
drinking (a plastic container such as high-density
polyethylene is a good choice for fluoride etching
solutions).
There are commercially available antidote creams
(calcium gluconate or equivalent, also cold
saturated magnesium sulfate solution) which can be
used for first aid for fluoride burns.24 Calcium
antacid tablets can be used to stabilize etching
solution prior to disposal (the calcium forms an
insoluble fluoride salt).25 Note that lapidary
techniques such as tumbling may provide an
alternative to chemical etching, depending upon the
bead and its features. Etching solutions are but one
of a host of chemicals which may find use in
beadmaking. They are a good example of the need to
understand the specific hazards of each chemical,
and to use appropriate protective equipment and/or
controls such as ventilation.
Moderate Risk Safety Issues:
First, keep in mind that every safety issue I cover
is important. Items in this section, if ignored, can
still cause considerable trauma or property damage.
Burns and Cuts
Burns from hot glass, followed by cuts, were the
most common health complaints of SGB members who
filled out a survey for NIOSH during the 1998 SGB
Gathering in Corning, NY.17 Working with a flame
whose temperature can be thousands of degrees means
you must exercise extreme care when manipulating
your work in the torch. Avoid situations where it is
difficult to see the flame (for example, working
outside, or wearing too dark a lens). Many
beadmakers keep a container of water by their work
space so they can mmediately cool any burned area.
Burns can also happen when you accidentally touch
hot glass. Here is where good work habits help -
always lay the hot end of a glass rod on a rod rest,
with the hot end away from you. Be sure you don’t
place the rods directly on a surface where they can
roll off and burn you or your studio. Exercise the
same good habits when using tools such as a tungsten
pick, mashers, pliers, and so on - always place the
hot end away from you, on a rest, or in a holder.
Cotton clothing, a leather apron, or similar
materials are preferred over synthetics like
polyester or acrylic.8,9,10
Damage to property can be avoided by an
appropriate work surface and flooring. A
nonflammable cover for your table or bench, such as
sheet metal, stainless steel, ceramic tile, etc. are
preferred.8,9,10 A metal plate can be used to cover
carpeting or wood floors. Floor surfaces such as
ceramic tile, concrete, or brick are also excellent.
In general, select materials for your studio which
are non-flammable. Kilns may be placed on bricks,
concrete pavers, etc. both to elevate them to a
convenient height and to protect flooring. Always
follow manufacturer’s directions concerning
clearances from walls and other surfaces. A smoke
detector is highly recommended for your studio. (And
even though it is my opinion that your beadmaking
will not produce dangerous levels of carbon monoxide
if you follow the ventilation guidelines above,
carbon monoxide etectors are readily available and
inexpensive, so they should certainly be in every
home).
Glass is usually ordered as rods, and these often
have sharp ends. Also, after pulling stringers or
lattticinos, the ends can be pointed and sharp. When
unpacking rods, it is best to wear gloves (leather,
also special cut-proof gloves are available). Have
your glass rod and stringer storage arranged so that
you can’t be cut by protruding ends. If you need to
cut glass, again protect your hands and wear eye
protection. Watch out for small
pieces or shards of glass on your floor (it always
amazes me how many of these I find when I venture
into my wife’s studio!).
Electrical Hazards
Most beadmakers start out with just a torch, glass
rods, some mandrels, and a bucket of vermiculite or
fiber blanket. If they stay with beadmaking for any
length of time, a host of electrical devices begin
to be added to the studio. The most important is the
kiln, used to anneal glass beads and to warm rods
up. Be sure to select a kiln whose electrical load
(measured in amperes, A) is not greater than the
circuit you will be connecting it to. Keep in mind
any other electrical devices you already have that
are sharing that circuit. It may be necessary to add
a circuit just for your kiln.
Other appliances which use electricity to heat
generally have fairly high electrical loads - hot
plates, crock pots, space heaters, and so on. These
devices, added to things like lighting, your
ventilation fan(s), a television, or stereo, can
quickly use up the rated load capacity of the
circuit or circuits in your studio. Never substitute
a larger fuse for the rated fuse if your electrical
system uses fuses. If your house uses circuit
breakers, constantly tripping breakers are a warning
that you may be exceeding the capacity of your
circuits and should have additional circuits
installed by a qualified person.
Note that some electrical devices, such as a
kiln, also may present shock hazards due to exposed
elements. And of course, devices which heat can
inflict painful burns. It may be possible to switch
elements to the kind that are silica-encased, or at
a minimum place barriers between the elements and
where your beads on mandrels go. The solution may be
as simple as raising or lowering the surface within
your kiln that you place beads on - most ceramic
stores sell spacers, supports, and so on.
Ergonomic Concerns
“Ergonomics” is defined as “the study of human
characteristics for the appropriate design of the
living and working environment”.21 In the context of
beadmaking, it includes a whole host of factors -
the height of your chair and table or workbench; how
your studio is lit; the manner in which you make
beads; the angle you have your torch set at;
diameter of mandrels you use, etc.
The repetitive twirling of beads on mandrels,
coupled with the “pinch grip”, can ventually cause
problems for some people.26 Some references
recommend a mandrel holder or wooden handle, giving
you a wider diameter to grip. It is also important
to take
frequent breaks, and to “listen to your body” if you
experience numbness in your fingers, ands, or arms.
If you experience such symptoms, this may indicate
you are overdoing it. Check to be sure you are not
resting on hard surfaces - cushioned armrests at the
right height are available. An adjustable height
chair with comfortable seat is highly recommended.
Proper posture can help alleviate neck and back
strain. The book by Dunham10 has an Appendix with
exercises and advice to avoid “stiffness, aching, or
pain”.
Just as staring at a computer all day can give
you eyestrain, so can extended sessions at the
torch. Good lighting can help in this regard, and
the protective eyewear mentioned earlier can deal
with the light from the torch.
There are numerous other areas that can bear on
how comfortable and safe a workplace you have. By
organizing your glass, tools, and accessories so
they are easy to reach, you can avoid awkward
postures or over-reaching. Analyzing how you work,
or having someone watch you, can help identify
ergonomic issues.
Pregnancy - Special Precaution
Since the majority of glass beadmakers are women, it
is not surprising that the question comes up of
whether it is safe to continue making glass beads
while pregnant. If you have followed all of the
previous safety guidelines, especially ensuring your
studio has
adequate ventilation, then it may be permissible for
you to continue beadmaking. This should only be done
after you discuss this with your doctor. Be sure to
fully describe any chemicals, special techniques,
and so on that are part of your repertoire.
Pregnancy
is not the time to get fancy and try, for instance,
metal fuming for the first time. The developing
fetus is particularly sensitive to exposure to many
agents, and thus any decision must be carefully
considered by the pregnant woman in consultation
with her
physician.
Children and Pets
Use caution in allowing children and/or pets near
your beadmaking area. Many of the areas where you
need to be careful can be downright dangerous for
your children or pets. They may also distract you
enough that you accidentally burn yourself in the
torch, or
perhaps them. Bear in mind that some things, such as
etching solution, can cause severe injury or death.
Minor Safety Issues:
Skin Rashes and Skin Irritation
A number of individuals have described skin
rashes, blotches, or other reactions to their skin,
usually on their face, when making beads. Some
people have attributed this to UV radiation, but as
noted above, actual measurements do not support
significant UV
emissions from most beadmaking processes. Therefore,
wearing sunblock is unlikely to help with these
symptoms, although the moisturizers present may help
somewhat. In my opinion, there are several potential
causes of skin irritation. First, the rash may be an
indicator that some aspect of your studio set-up
needs attention. If your ventilation is inadequate,
then reactive gases such as nitrogen dioxide, or
heat from your torch and electrical appliances, may
build up. These can lead to simple heat rash, or to
a more complex interaction of the combustion gases
and /or heat with your skin.
This may also be compounded by use of some
personal products, such as make-up and prescription
medicines.17 In rare cases of individual
sensitivity, there may be reactions to factors
which normally do not cause problems for the
majority of people. You may need to study your
working habits for clues (for example, when making
beads do you sit so that your face is very close to
the torch?). Experimentation with protective
equipment such as
a full faceshield, barrier creams, and so on may
provide solutions. Medical advice may be necessary
in extreme cases.
Dusts and Nuisance Particulates
Vermiculite and ceramic fiber blankets are often
used to slow-cool beads during beginning beadmaking.
As with any particulate, excessive exposure should
be avoided. Particle size, as well as the chemistry
of the particle, are very important determinants of
the hazard posed by an inhaled particulate. The
human body has multiple lines of defenses since we
must inhale air to stay alive. Our defenses are poor
against very fine particulate, and once the
particles get to less than 10 microns, they are
increasingly able to be drawn deep into the lungs.
Fibers are a special case, and there has been
tremendous advancement in the understanding of fiber
toxicity in the last 15 years.
At least one location where vermiculite was mined
was found to also contain asbestos. But in general
vermiculite does not contain appreciable levels of
asbestos fibers. It is normally considered a
nuisance dust by industrial hygienists. As most
beadmakers
advance to kilns to properly anneal their beads,
irritation from vermiculite dust becomes a
non-issue. Bead release materials are mostly
clay-based17, and therefore also classified as
nuisance dusts. Your glass itself may contain
significant amounts of heavy metals to get the rich
colors.23 But this glass is usually not present in a
form that can be inhaled (see, however, enamels and
frits note below).
Ceramic fibers may be used as blankets to cool
beads, as well as in kilns for insulation.
One should be careful to avoid exposure to
refractory ceramic fibers or dusts from kiln
insulations. The degree of hazard depends on the
fiber dimensions, as well as fiber chemistry,
durability, and inhaled amount. Fibers which are
relatively large get stopped by the body’s defenses.
Fibers which are sufficiently small may bypass the
defenses, and then may cause harm depending upon
their chemistry and how long it takes the body to
clear them. The International Agency for Research on
Cancer recently completed a comprehensive review of
several fiber types. While the rating was downgraded
for fiberglass and rock and slag wool fibers, the
rating for refractory ceramic fibers was left
unchanged as “possible human carcinogens (Group
2B)”.27 The most insidious hazard of
high-temperature insulations for kilns and glory
holes is the slow formation of crystalline silica at
the high use temperatures. Crystalline silica is a
known human carcinogen, and therefore activities
such as rebuilding a kiln must be done with
appropriate personal protective equipment.
Exposure to many sources of dusts can be minimized
by having these operations take place where your
ventilation system can draw the dust away from your
breathing zone. Clean-up should be done by
vacuuming, preferably with a HEPA (high efficiency
particulate air) filter-equipped vacuum, mopping, or
wet wiping, as opposed to blowing off with
compressed air, to avoid re-suspending the dust in
the air.9
Special Note: Enamels and Frits
Some materials are used as powders or finely ground
materials, and may have a fairly high fraction
present as fine particulate.23 Often heavy metals
may be used in these substances to obtain the
colors, and therefore one should be careful to avoid
inhalation.28 Depending upon how you use these
materials, you may need to wear a respirator during
these operations. (Note, preferably a half-face
respirator with HEPA particulate cartridges, this
type is more likely to achieve a good seal. A “dust
mask” may suffice, but it is usually more difficult
to ensure an adequate seal around the face. Men, it
is almost impossible to get an adequate respirator
seal if you have facial hair. The NIOSH website in
Recommended Reading has additional information on
respirators).
Insufficient Data To Rank The Hazard -
Specialized Techniques and Tools:
I have tried to present a balanced and comprehensive
review of the safety issues that the majority of
glass beadmakers need to be aware of. But there are
certainly numerous examples of beadmakers doing
specialized work. In these cases, I am unaware of
sources
of reliable information to adequately assess the
relative risk. Sometimes the operation and materials
used may indicate the need for special care - for
example, fuming with metals. While not directly
related to fuming in beadmaking, a recent article
looked at
“copper exposure and metal fume fever”.29 If you do
fuming, this article has a large umber of references
to literature on metal fume exposure.
The book by Dunham includes some information on
other lampworking techniques besides beadmaking, as
well
as use of chemicals to color glass.10 If you are
using any chemicals, for example, tetraisopropyl
titanate (and similar mixtures) be sure to fully
understand the specific hazards of the material: Is
it corrosive? An inhalation hazard? Is it flammable?
An MSDS from the manufacturer, or the sources in
Recommended Reading, can help you find this
information.
In other situations, for example using lapidary
tools to cut, shape, and polish glass, you should
consult existing literature in this field for
specific safety information. Where I felt there were
already ample references available (jewelry,
lapidary, glassblowing) I did not repeat this
information in the glass beadmaking context.
Finally, the NIOSH report from the Corning Gathering
includes a number of references to studies of health
effects on glass workers and art glass workers.17
Summary and Disclaimer:
I hope you will find this information useful and
that it will help keep you safe. As I mentioned in
the introduction, the person who bears full
responsibility for the safety of your operation is
you. Virtually everything in your studio is under
your direct control, and except for rare instances
of equipment failure, your safety depends upon you.
In short, give the same interest and focus to safety
as you do to new beadmaking challenges, and you can
look forward to a lifetime of fun and reward from
making glass beads.
Extra care has been taken to provide references
for the facts and opinions in this safety overview.
This will enable you to consult the references, and
also to do additional research if needed. I invite
you to question, to challenge, to do further
reading. One area to keep in mind is that I do not
personally make beads, but rather strive to keep my
wife’s studio accident-free. Any errors or omissions
are unintentional, and any responsibility associated
from these or other assertions in this overview are
specifically disclaimed.
Dedication:
This effort is dedicated to my wife, Pamela, and to
all of those other beadmakers out there who use
their time to be creative and bring beauty and art
into the world. We need more people like you!!
Special Thanks:
Thanks to Vince Henley for taking the time to review
this information and sending me his comments. Vince
has been a great resource for safety and technical
information to the beading community on the SGB (now
ISGB) Forum. I appreciate your help Vince, and in
virtually all cases followed your sage counsel!
Stan Wolfersberger
January 2002
References:
1. The Condensed Chemical Dictionary, 10th Edition,
G.G. Hawley Ed., 1981.
2. Fire Protection Handbook, 18th Edition, NFPA, A.E.
Cote, Editor, 1997.
3. “Overfilling Prevention Devices (OPD) For
Consumers”, National Propane Gas
Association, 2000.
4. Vince H’s favorite website when reminding
beadmakers to handle propane safely:
.federatedrural.com/propane/litigation.htm
5. Handbook of Compressed Gases, 3rd Edition,
Compressed Gas Association, 1990.
6. Personal Communication, Vince Henley, 2002.
7. Gas Data Book, 6th Edition, Matheson Corp, 1980.
8. Making Glass Beads, Cindy Jenkins, 1997.
9. More Than You Ever Wanted to Know About Glass
Beadmaking, James E. Kervin,
1996. (There is a 2nd Edition available now, but
it’s not on our bookshelves yet!)
10. Contemporary Lampworking - A Practical Guide to
Shaping Glass In the Flame, 2nd
Edition, Bandhu Scott Dunham, 1997.
11. The Bead Release, Vol. V, Issue 4, Fall 1998,
“Safety Information - NOx Emissions
From Your Torch”, Stan Wolfersberger.
12. Proceedings of the American Scientific
Glassblowers Society, June 1996, “Detection
of NO2 by Open Path FTIR During the Glassblowing
Process”, E. Billiot et al.
(Thanks to Doni Hatz for bringing this one to my
attention!)
13. 2001 TLVsTM and BEIsTM - Threshold Limit Values
for Chemical Substances and
Physical Agents & Biological Exposure Indices,
American Council of Governmental
Industrial Hygienists, 2001.
14. The Bead Release, Volume VI, Issue 4, Fall
1999, “Ventilation Basics”, Stan
Wolfersberger.
15. The Bead Release, Volume VIII, Issue 2,
Spring 2001, “Ventilation for Beadmaking:
How Much Do You Need?”, Stan Wolfersberger.
16. Industrial Ventilation - A Manual of Recommended
Practice, 18th Edition, American
Council of Governmental Industrial Hygienists,
1984.
17. NIOSH Health Hazard Evaluation Report HETA
98-0139-2769, The Society of Glass
Beadmakers, Corning, NY, C. Eugene Moss and Nancy
Clark Burton, December
1999.
18. Journal of the American Industrial Hygiene
Association, Vol. 61, No. 1, “Infrared
Radiation Exposure in Traditional Glass Factories”,
R. Sisto et al.,
January/February 2000.
19. NIOSH Health Hazard Evaluation Report HETA
95-0119-2554, Glass Schell Fused
Masks, Houston, TX, NIOSH, 1996.
20. The Bead Release, Volume IV, Issue 4, Fall
1997, “Letter re: Proper Eye
Protection”, E. Weisbart.
21. Fundamentals of Industrial Hygiene, 3rd Edition,
B. Plog, Ed., 1988.
22. The Bead Release, Volume IV, Issue 3, Summer
1997, “Your Health and Safety re:
Eye Protection”, Bob Aurelius. (The Aura Lens
website has some very useful
information, including spectral transmission
characteristics of their protective
eyewear. See the ISGB website below for a link to
the Aura Lens site)
23. NIOSH Health Hazard Evaluation - Pamela
Wolfersberger, C. Eugene Moss and
Nancy Clark Burton, March 2000.
24. MSDS for Ammonium Bifluoride, J. T. Baker Corp.
25. Destruction of Hazardous Chemicals in the
Laboratory, George Lunn and Eric
Sansone, 1990.
26. Lapidary Journal, Vol. 53, No. 7, “Special
Tools, Special Care”, Kristina Logan,
October 1999.
27. International Agency for Research on Cancer, see
press release at their website,
http://www.iarc.fr/
28. MSDS for Thompson Enamel, Thompson Enamel Corp.
29. Journal of the American Industrial Hygiene
Association, Vol. 61, No. 6, “Copper
Exposure and Metal Fume Fever: Lack of Evidence for
a Causal Relationship”, J.
Borak et al., November/December 2000.
Recommended Sources for Further Reading or
Research:
The most readily available information for the
average person will be found via the Internet. Be
very sure that the site you are using is reliable.
Anyone can put anything out there, so if possible
stick to organizations such as those listed below:
http://www.cdc.gov/niosh/homepage.html =
National Institute for Occupational Safety and
Health, the research arm of OSHA (these folks did
investigation at Corning in 1998).
http://www.osha-slc.gov/html/subject-index.html
= Index to the U.S. OSHA (OSHA= Occupational Safety
and Health Administration).
http://www.epa.gov/iaq Environmental Protection
Agency, Indoor Air Quality
http://www.ccohs.ca Canadian Center for
Occupational Health and Safety
http://www.aiha.org American Industrial Hygiene
Association
http://www.aws.org American Welding Society (Go to
Technical
Department, then Safety and Health Fact Sheets)
http://www.nsc.org National Safety Council
http://www.nfpa.org National Fire Protection
Association
http://www.asse.org American Society of Safety
Engineers
http://www.who.org World Health Organization
http://www.iarc.fr/ International Agency for
Research on Cancer, a
branch of the World Health Organization
http://www.acgih.org American Council of
Governmental Industrial
Hygienists
http://www.naima.org North American Insulation
Manufacturer’s
Association, good source of literature on man-made
mineral fibers
http://www.npga.org National Propane Gas
Association
http://physchem.ox.ac.uk/MSDS/ Oxford University
“across the pond”; I ran across their Safety
Information site in 1999, and it is still there, and
very good.
http://www.lni.wa.gov/wisha/p-ts/Ventilation/default.htm
A nice site with ventilation basics overview that I
mentioned in my article, Ref. 15.
http://www.safetyonline.com Safety Products and
such
http://www.isgb.org International Society of Glass
Beadmakers (of course!)
They have links to resources, suppliers of
protective eyewear, and so on.
Books (in addition to those in References):
Handbook of Toxic and Hazardous Chemicals and
Carcinogens, 3rd Edition, M. Sittig, 1991.
Sax’s Dangerous Properties of Industrial
Materials, 9th Edition, R.J. Lewis Sr., Ed., 1996.
The Dose Makes The Poison - A Plain-Language
Guide to Toxicology, M.Alice Ottoboni, 1984.
Patty’s Industrial Hygiene and Toxicology, 5th
Edition, E. Bingham, B. Cohrssen, and C. Powell,
2001.
Ventilation for Control of the Work Environment, W.
A. Burgess, 1989. Laboratory Fume Hoods, A User’s
Manual, G. Thomas Saunders, 1993.
Industrial Ventilation, 2nd Edition - A Self Study
Companion to the ACGIH Ventilation Manual, D. Jeff
Burton, 1984.
Ergonomics for Beginners, A Quick Reference
Guide, J. Dul and B. Weerdmeester, 1997.
Ergonomic Design for People at Work, Vol. 1 & 2,
Eastman Kodak Col, 1983. Human Factors in
Engineering and Design, M. Sanders and E. McCormick,
1993.
Indoor Air Pollution - Characterization,
Prediction, and Control, R. A. Wadden and P. A
Scheff, 1983.
Indoor Air Quality and HVAC Systems, D. W. Bearg,
1993. Managing Indoor Air Quality, S. J. Hansen,
1991.
Indoor Air Quality Control Techniques, W. J. Fisk et
al., 1987. Indoor Air Quality Workbook, Rev. 2nd
Printing, D. Jeff Burton, 1991.
Copyright 2002
The author and ISGB will allow reproduction of this
article, as it may be a valuable supplement to
beadmaking classes. Please reproduce the article in
its entirety, so that your students can understand
the context of all comments, as well as have access
to the references and sources for additional
research in Recommended Reading.
Stanley J. Wolfersberger Final Version Completed
January 5, 2002
