Safety
Rev. 2001-10-22, 2003-03-30, 2005-02-02, 2006-06-26, -10-29
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A
WARNING:
Working glass is inherently dangerous, involving heavy materials
that can be razor sharp, so hot that damage can be done before
feeling occurs, with chemicals immediately poisonous, dusts that
can damage the lungs, and heat sources that can wreck the eyes.
Understand the safe practices required and use them to blow
beautiful glass.
FIRST AID - [Burns] Getting
a piece of glass out can be one of the most difficult removal jobs. It is hard
to see and hard to grasp with tweezers and if it is sitting on a nerve can be
constantly painful. Unless you are very comfortable folding yourself into a
position where you can see the place, not just touch it, you will have to have
someone else do the work. If you can do it yourself or get some one, you need a
very bright light that can be moved around a bit, like a halogen reading lamp or
intense flash light. You will need a strong thin sewing needle (or a scalpel but
most people don't have one) and antiseptic like hydrogen peroxide or alcohol.
Clean the skin and the tool and use the point of the tool to go in a bit and
lift to cut the skin in the area creating a small trench. Use the fingers of the
other hand to spread the trench. While working, the person doing the opening
needs to listen and feel for the scrape of metal on glass as well as looking for
a different texture or gloss. It may hurt to open and to try to move the glass
if it is there. If damage has been done, but the glass is out, simply opening
the place may take out dirt or other floor stuff pushed into the wound - in
which case clean with Hydrogen Peroxide and bandage over.
If the glass is there, it may be difficult and painful to dig under it with the
tool or to grip it with tweezers (also sterilized.) If it becomes too painful to
work on, clean and bandage the wound and go to a walk in clinic or emergency
room or see your doctor and let people work on it.
andrea mcandrews wrote:
Hi, I just started taking a glassblowing class and am interested
in pursuing it further, hopefully even to get a job as an
apprentice. I was wondering if you know any of the health hazards
that go along with working with glass. I was told that the
silicon in colored glass is pretty bad for you. Right now though,
I am just working in clear, so I was wondering if you could help
me out.
Thanks a lot,
Megan McAndrews:)
CHEMICAL RISKS - The silicon in
colored glass is irrelevant. The chemicals used to make colored
glass or to take the color out of batch are far more dangerous
than the silicon. Many glass colors contain lead oxide as it
expands the range of coefficients of glass that the color will
work. Colors like red or orange are made with cadmium in some
cases, a heavy metal poison.
The silicon in glass batch (the sand based powder melted to
make glass) is dangerous to the lungs and thus it is advised that
a respirator be worn when charging a furnace and an effort be
made to avoid scattering the stuff around the studio. Most batch
contains antimony oxide, arsenic oxide, or some other chemical to
react with chemicals that cause color so the glass is clear or
"white" metal and these are far more dangerous, short
term, than silicosis.
When glass is ground to change its shape or even out a base (cold
worked), both the silicon and the heavy metals may be released.
Since water is required when cold working glass to keep it from
heating and cracking, normally the dust is never in the air, but
is carried off in the water and collected as sludge in whatever
trap method is used.
RISKS -
There is some risk assumed from the glare of the furnace (or
torch heated glass) since the light intensity exceeds OSHA
standards and a number 4 welders shade is suggested for actual
exposure at the furnace. On the other hand, most glass workers
spend relatively little time at the furnace or glory hole. I use
a full face plastic shield, #5, both for the eye comfort and for
a cooler face; I have become adept at flipping it up and down.
Some other people use flip ups on their glasses or mount a filter
as a view panel at the edge of a metal heat shield before the
furnace.
- Eye Protection
- Every glass worker should have several levels of eye
protection: at a very minimum, break resistant glasses to
save the eyes from glass fragments. Furnace workers,
according to tests, should be using at least a #3 and
preferably a #4 welders shade to observe the furnace and
gloryhole. I do this with a relatively low cost ($25)
plastic shield on a Jackson 170-S (not the newer 170SB)
head band with Glendale Irex (Blue Diamond) 862 shield
stocked in #5. The full face shield is also nice in
holding off the heat, but I got the idea from
a couple in
Michigan who cut off the lower half of the shield so they
don't have to raise it to blow. I have become adept at
raising/lowering the shield quickly.
Glasses commonly used for lampworking are referred to as
didymium glasses. This material specifically blocks the
yellow sodium flare that blocks viewing the glass in the
flame. It does not, in and of itself, block UV or IR, and
must be part of shading or other design factors to
produce full protection.
Some workers wear welding clip-ons or use a flat piece of
welding glass in a frame at the yoke to look through.
According to tests, UV is not a problem, IR is too high
and protective choices should be made. Many glassworkers
use sunglasses or nothing, for better or worse. If your
eyes show signs of drying or pain or after effect images,
you should be using more protection than you are.
Cataracts from IR were found to be a problem at the end
of the manual glassblowing of bottles (1870-1890's) as
people lived longer due to better health so more obscure
problems could come to the surface.
- Clothing
- It is recommended that glassblowers wear cotton or wool
clothing rather than nylon or polyester. Part of the
reason is the way that natural fibers hold sweat. But
also nylon can melt in the heat and if it sticks to the skin
is very painful. It is easy to say that the heat will be
avoided, but easier said than done. I have a light jacket
I wore against the fall chill and I melted a portion of
the cuff without damaging my hands - the insulated fabric
rose in temperature from the radiated heat of the
gloryhole while my blood flow kept my hands cooler. Many
glassblowers work in short sleeves and short pants and
pull on a cotton sock with the toe cut out to protect the
arm when working bigger pieces but this provides minimal protection from
a flying piece of hot glass or an errant hot tool.
A recent discussion on one board mentioned the risks to women of non-cotton
underwear - mentioning specifically a bra that melted from the heat and left
a scar. Reflective cloth for sleeves and under shirts is now
available 2004-04-13
- Insects
- If the building has open ventilation, then insects have to be
considered. The three insects that get the most publicity are
mosquitoes for West Nile fever, ticks for Lyme disease, and small spiders for
nasty little bites, but problems can also arise from bees or wasps taking up
residence. Mosquitoes may breed in standing water so
treating the water should be considered.
Insecticides and repellants judicially used will reduce the risk. Mud
dauber wasps (very thin waists) are harmless, but will clog pipes with mud
plugs and I recently found a torch with webs inside it clogging small
pathways. I make wind chimes also and something is dragging grass into
the tubes hanging in mid-air, stuffing them full and laying eggs that hatch
into what look like tiny grasshoppers. 2006-06-26
- Heat
- Heat is different from burns in that
heat is an overall effect on the body, while burns (normally in
glasswork)
effect a small part of the body. Depending on how a
glassworker works, the heat exposure of the body can be
very high. When I was blowing glass in mid-summer in the
Hill Country of Junction, Texas, it was hot (100ºF+) but
very dry. I normally sweat to the dripping point in north
Texas, but drinking close to a gallon a day, I remained
dry down there. In an enclosed studio, the temperature
can be well above room temperature and at or over 100F
near the furnaces where the worker functions. Good
ventilation should be provided, with controlled air flow
for both furnace area and working area. There should be a
good air supply also and furnace area air should not come
from the working area as people may find cold winter air
chilling and close down required intake air. One person I
met in my early years was unable to blow during the day
because of what a prolonged exposure to heat - all day -
did to his electrolytes before he was thrown in the
hospital.
Continuous heat in a studio can dry out wood structure and damage roof
material increasing the risk of fire. One tar roofed academic studio
regularly dripped tar from the combination of summer and furnace heat.
2006-06-26
- Burns
- One of the things that people get concerned about is the
mass of white molten glass being carried on the end of
the pipe and the number of people on the floor. Yet, in
my years of working on the floor and talking with people
about burns, I rarely hear of a story of someone
burned from that hot glass. I believe part of the reason
is that hot glass drips if not kept rotating, so it is
watched constantly and thus the handler is ready to move
it away. Most of the more serious burns I have heard of (anf
experienced) have come from picking a pipe or punty from
the wrong end [mistaking the dark heat damaged end for the dark rubber
handle] or from rolling a pipe and hitting a leg
while sitting working. Mild burns from cooling hot glass
on the floor, etc., occur also.
Please understand that most glassblowers experience First
Degree burns frequently, either from working large glass
or pausing too long at the furnace or glory hole.
First Degree - Reddening of the skin with a continuing
burning sensation - heavy sunburn
Second Degree - Small to large blisters - damage to
surface of skin.
Third Degree - Blackening/charring/cooking of skin -
damage to flesh under skin - shock likely.
It is a good idea to keep standard first aid equipment on
hand, including soothing antiseptic sprays designed for
mild burns. A serious burn should be plunged/soaked in
cold water (not ice) as soon as possible (if the skin is
not broken, any water may be ok but clean water is better), to drop the body
temperature, then treated medically as needed. Aloe is frequently
mentioned for minor burns and some people keep a plant in the window instead
of a tube in the medicine chest.
- Fire
- The ideal glass blowing studio could have everything made of concrete
and metal and still be at risk from portable propane bottles, packing
materials and cloth decorations and wooden tables and shelves. There
is a risk of fire from constant low level heating of wooden materials and it
is common for the temp up near the roof to be up around 200F. An indoor
outdoor thermometer measuring up there may be helpful as a warning. I
use one with a 10-12' probe on a wire to show me in a lower hallway the
attic temps in my home.
Good ventilation is a safety feature for fire as well as heat prostration.
Metal truss roof beams, sheet metal roofing and fire rated sheet rock on the
walls are important. A glory hole or furnace with a gas supply that
does not cut off on air failure can have a flame roaring out the front for
many feet, igniting materials including clothing. Molten glass falling
on a wood floor can start a fire as can hot glass or pipes placed in a
barrel that holds trash. A hose to supply water will help with cleanup
and attack most fires in glass studios.
- Gas
- Natural gas rises, propane sinks in still air. Check all
connections with soapy water, not a match. Clear out if
gas is smelled, provide ventilation, turn off open
flames, and track down the leak. If nothing else works,
get the gas company in. Carbon monoxide from improperly burning
flames is about the same density of air; more likely from low flames - water
heaters or pipe - than furnaces or glory holes. Also from car exhaust when
car inside building. Detector needed.
- Cuts
- Cold glass has sharp edges. At a minimum, inexpensive
leather gloves should be kept on hand. Long cuff padded welding gloves
cost under $10, eventually getting stiff if heated a bunch. There are gloves
on the market with rubber dots on the surface that help
grip glass and keep it from slipping. There are also
gloves that have Kevlar or other tough fibers to resist
cutting through to the hands. If you are like me, keep
band aids handy.
Security
Security here means securing your property as much as possible
from theft and vandalism. This is not meant to be an essay on burglar
alarms and high tech video cameras, although those can be useful. A
feature of some alarm systems is the ability to place several phone calls in the
event of a problem and people have used these to be warned that a furnace has
gone down or that power has failed - obviously such a system must have its own
battery and more expensive systems will use a cell phone to call to avoid the
burglar who cuts the phone line coming in.
A glass blowing studio's most valuable contents are probably the
glass objects, attracting a vandal, and the tools. But the tools really
only have value to a glass blower and the most likely threat is a person
familiar with the studio who has been fired.
It is my recommendation that security begin with good artificial
lighting and a control system for inside lighting that makes it as uncertain as
possible to determine whether someone is in the building or not. This
includes being able to turn on and off bathroom and office lights via a timer.
I like the X-10 system sold by Radio Shack as Plug n'Power and by Fry's and
others as X-10. These units can plug in or replace outlets and light
switches and are controlled by signals sent over the power lines, so no
additional wiring is needed. A single control unit can manage up to 16
remotes and while there are timer controls available, I much prefer the unit
that connects to a computer for programming (and can be unplugged for use to
free up a comm port) since setting and resetting the standalone units I find a
hassle.
Locking up the building should be designed in to construction
plans, but it can be implemented later. I recommend that only one door
have an exterior key lock and all the other openings be locked with slide bolts
or bars that can only be accessed from the inside. Thus a single door is
used for entrance and final exit and that door is made as tough to get through
as possible. Be aware that a really determined thief can get through
anything, given enough time or using enough force. We have all heard
stories of people using a stolen car or truck to smash in the front of a store
to make off with jewels, ATM's, computers or cigarettes. Whether a glass
studio is likely to attract that kind of effort, a battery powered reciprocating
saw with a carbide blade or a portable cutting torch can go through most metal
guards and locks and a sledge hammer can put a significant hole in a sheet rock
or cinderblock wall, given enough time. Security lighting can reduce the
time available to work unobserved.
The main door to a studio should be as heavy as possible and
should open inward to reduce access to the hinge pins and to make prying the
door more difficult. The frame should be solid so that it can not be pried
sideways to release the locks. A solid core door or a steel cased door
should be used and unless the door is especially strong, the deadbolt lock
should be installed on the inside face of the door, not within the thickness of
the door. There is a style of deadbolt that looks ugly, but actually pins
the door to frame. Do not depend on a snap latch to keep people out.
Windows should have a steel grill on the inside and at least one
per room, clearly marked, that can be quickly released in the event of
emergency, as you don't want someone to be trapped in a room when a fire or gas
leak blocks other exit. But the grill release must be positioned so that
is can not be reached by someone who has broken the glass and is reaching
through the grill. [As I learned in college, a lock set in a grilled door with a
shield may well be opened with a properly shaped tool passed through the grill
and moved from hole to hole around the lock. The release should be easy to
move or lift from inside and hard to work if worked near the window - like a bar
hanging down that lifts easily from the bottom end but hard near the pivot.]
Each door will have to be examined for the best way to secure
it. If forced to deal with a pair of doors that open out, a security bar
that spans the inside frame and drops down snuggly over four hooks, as used at a
hardware store I once encountered, may be needed to keep the doors in place as
pins may not. Garage type sectional doors, while admitting a lot of air,
have wide enough gaps that it is often possible to attack the latches or bolts
from the outside. Slide bars that move into holes in the track or added
brackets on the side may be needed. 2006-10-29
Contact Mike Firth