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updated wed 30 apr 97


John Baymore on fri 18 apr 97

Richard Ramirez wrote (in part):

....... used by my school's custodial staff to better service our
department. ...... ...... Areas of concern: #1- Floors=regularity
of sweeping and wet mopping, are sweeping compounds used?, how often dust
mop heads changed?, do you use a vacuum? type/,how often?,are your floors
conceret?, does the custodian uses a respirator?

Generally speaking, floors in a ceramics studio should never be swept, only
cleaned by VERY wet methods (except as mentioned below). The fine
particles that do the damage to our lungs (particularly microcrystaline
silica, but other stuff is present too) are not visable to the eye, and
stay in the air for a LONG time after the visable stuff has settled
out...... whole day at least. This lack of seeing "dust" gives a false
sense of safety.

The allowable concentration for silica dust in the air (in a school OSHA is
an issue) is very low......... so the dust is considered very toxic.
Sweeping compounds don't do enough to be considered a safe practice with
such a hazardous material, although they reduce some of the dust. If a
room is swept, the custodian gets the greatest exposure over the short
term (he is there in the worst of it, but only shortly), but the faculty
and students using the room after the so-called "cleaning" get a sustained
dose over much longer hours (lower levels over MUCH longer time).

do you have and use a wet-vacuum?, type?,

Never use a regular vacum cleaner. A wet vacum is good....... just make
sure it is ONLY used on very liberally wet stuff. A regular vacum cleaner
(or a wet vac) will whip dust into the air worse than a broom if it hits
any dry stuff. The only exception is a specially made vacum for ceramics
studios with a HEPA filter in it. The problem with these expensive units
is that if used for general floor cleaning instead of wet mopping, you will
go through a lot of $200.00 plus .33 micron filters very fast, even with
the usual pre-filter bag.

..... air purification units.......

Make sure you get the HEPA filter type. These are a great idea AFTER you
have reduced the sources of dust to the bare minimum by other methods like
wet cleaning, changing dust producing habits, and putting in localized
pickup vents on dusty operations. If the dust has gotten mixed into the
room air so that you need a purification system (usually hung at ceiling
level) to get it out of the general studio air, you have a serious health
problem you have failed to address.

Your lungs are breathing the same air that the purification unit is sucking
in. If it is clogging its filters frequently, so are your lungs! You
can't change those filters .

These units should be the LAST line of defense to the dust problem, not the
first, unless there is no feasible way to control the dust by other means.
In other words, it would be better than not doing anything at all, but a
really poor choice as a primary means.

Simple regular wet cleaning is the first step.

#4-Trash collection: ............. do you throw, slurry,
glaze, dust, in with paper?

This is a "smoking gun". Legally, there are regulations about disposing
of a lot of the materials we use in ceramics. We are (much as we hate to
admit it) harardous waste generators. For schools and businesses (potters
who sell work) the government has specific laws that apply. Call the EPA.

A home hobbyist is (generally) exempted because of the small amount of
materials produced, and can just take the stuff to the local "dump" or
"hazardous waste collection day".

Not so a school or business. Certain things need a hazardous waste handler
to take them. (Barium carbonate is one of them!) And there is specific
paperwork documentation to be done.

I don't know of too many potters or schools that are compliant here.
Someday someone will take notice officially and we will all get more

As to my school, NH Institute of Art, floors are wet mopped, but not
frequently enough to suit the faculty liking. Constant battle, varies with
the mood of the custodian. Sometimes someone (well meaning student) grabs
a broom until someone yells! Amazing how they find a broom even though we
had all removed from the department .

We just ordered a Nilfisk HEPA vacum to add to the arsenal. The faculty
are working more emphasis on cleaning and its health benefits into the
general studio practices with the students.

The custodian used to sweep the floor in the past, and didn't wear a real
respirator, just a paper nusiance dust mask. An "education campaign" over
time has changed a lot. Talk to these people..... they don't know what
this stuff IS.

No purification units (yet). No general dilution studio ventition. A
local pickup on the hot wax area in the general studio space. Ceiling
mounted AC units in the summer (with general use filters), with a pretty
low speed fan, oriented not to direct the flow toward the floor of other
potentially dusty surfaces. Floors are vinyl tile. Doors kept open or
closed as the mood suits (much to the dismay of the photography studios
right next door!)

The President of the Institute knows Monona's name and we occasionally
"invoke" it. Usually works like a charm . (Didn't know you had that
kind of power, did you, Monona? )



John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA