Saturday, March 15, 2008

Basic Safety Principles

In general safety Aim for: a well laid-out, orderly workshop, well-lit by multiple non glare light sources, well-maintained equipment, electrically and fire safe, with low dust and few procedures involving solvents, with excellent local ventilation at the appropriate work stations (such as investing or melting areas), the use of work clothing, which is cleaned frequently, lots of personal safety equipment (earmuffs, shoe covers to protect against molten metal splashes, safety glasses etc.), different jobs and heights to work at over the work day, ergonomically considered working actions and a conscious attitude and consciousness of safety. Choose procedures that don't involve exposure to risks. Set things up so that you can't hurt yourself. Make safety a habit and then it won't seem like work. If you don't use a certain chemical or hazardous procedure in your shop, then you are extremely unlikely to get hurt by it. Substitute less hazardous processes and materials for more dangerous ones. If you have an accident or a near miss it needs to be recorded in your accident book and discussed so as to avoid doing the same thing again.

To escape unnecessary work, look for examples of people who have solved the same kinds of safety problems you have to solve, and see if you can adapt some of their ideas and approaches for your own small shop. Look for models around you.

There are dusts you can see in the air. It is, however, the smaller, completely invisible particles that are the most dangerous. These, especially fibrous or jagged ones like asbestos, cotton and silica, are stored between the air sacs of the lungs. That is, you breathe them in and they will never escape again. Once there, they cause scarring, thickening of tissues, eventually stressing the heart because it is more work to breathe. Cristobalite (a rather vicious form of silica) exposure is considered a real silicosis hazard. It is a major component of casting investment.

Fumes are small particles of a material, often from metals that have been melted. These may be very tiny and can be breathed deeply into the lungs. Metal fume fever can be a real problem with molten metals. Metal fume fever can be caused by zinc, copper, magnesium, aluminum, copper, antimony, cadmium, iron and silver.

Dilution ventilation is used in many shops, where you open a window next to you, and another one elsewhere, so that air passes you on its way out. Dilution ventilation is not generally an effective approach. What we really want most of the time is local ventilation, which means a sucking device, slot or tube very close to the working area that is generating the dust, mist or fumes so they are sucked away as they are produced: removed entirely from the workshop and vented safely (i.e. not near a makeup air intake).

If you think you need a respirator to do something, red flags should be waving in front of your eyes and alarm bells ringing in your mind. If you have to use a respirator, there is something seriously wrong with your ventilation system and working processes. And when you take it off, whatever it was you were afraid of will still be there, an invisible dust (such as cristobalite investment) on all surfaces, so that merely walking past later will stir it up into the air so you can breathe it in. If you are using one, make sure it is correct for your face and for the dusts, chemicals and fumes you are protecting yourself from. Talk to your safety supply company representative, or better still several of them. It is easy to use the wrong respirator or to have an imperfect seal when you use it.

Eye protection in the workshop usually consists of using safety glasses and/or a face shield. Polycarbonate glasses are good. Aside from protection from sharp objects, flying chunks, dust, chemicals, fumes, liquids and hot metal splashes, we have to deal with glowing materials (infrared light), the blue flame of a high-temperature torch (ultraviolet light) and "sodium glare or flare."

Most glasses and polycarbonates will stop the ultraviolet. So will most contact lenses. The infrared is stopped by a "shade": numbers 2 and up have been suggested. It is important that one understands that a "tinted" lens does not offer infrared protection-only a shaded lens offers protection. McCann notes that "most recent recommendations are to wear the darkest shade number consistent with being able to see your work (ANSI Z87.1-1989" (McCann, Artist Beware page 216). Side shields that stop UV and infrared are also a good idea. The sodium flare, which is more of a problem for glass workers, is stopped by didymium glasses.


[get this widget]

0 comments: