This
is from Greg Rawls' website. He is a glass worker and a certified
industrial hygienist. A huge amount of practical information on
safety in glass working is available on his web site:
Ground
Glass
OSHA
classifies glass dust as a “Nuisance Dust”. Ground glass does
not cause silicosis. You can wear a respirator if you are concerned
about exposure.
Glass
is made from sand, which contains silica - a naturally occurring
mineral silicon dioxide (SiO2). Crystalline forms of silica, also
known as “free” silica, can contribute to the development of
silicosis under prolonged exposure conditions.
It
is important to understand the difference between glass and
crystalline silica because exposure outcomes are extremely different!
Glass is a silicate containing various other ingredients which have
been melted and upon cooling form an amorphous, or non-crystalline
structure. While silica (SiO2) is a primary ingredient in the
manufacturing of glass, when glass is formed under heat, the
crystalline structure is changed to an amorphous structure and is no
longer considered crystalline.
Ground
glass is rarely respirable because the particle is too big. Always
use wet methods when grinding glass! Water captures the dust.
Sometime other chemicals are used to add colour to glass such as
arsenic, lead, cadmium. These are usually present in low
concentrations and are bound to the glass and not readily available
but could present an exposure issue under some circumstances.
