Date: Thu, 4 Nov 1999 12:10:18 EST
Subject: Re: Offset spray powder inhalation hazards?
Spray powder does not pose any specific health hazards as it is simply potato
or corn starch. Its particle size is about 15 microns in diameter, which is
above the respirable size of 10 microns. This means that it presents only a
nuisance hazard and is subject to OSHA's Nuisance Dust standard which sets a
limit of 15 mg/m3 for the total fraction of dust and 5 mg/m3 for the
Also, the American Conference of Industrial Hygienists (ACGIH)'s 1999 safe
exposure limit for Particulate not Otherwise Classified is 10 mg/m3 for the
total dust and 3 mg/m3 for the respirable fraction. The ACGIH standard for
cellulose is 10 mg/m3 for the total fraction.
In order to definitely know the exposure concentration it makes sense to
sample the employee's work space for spray powder. The results of this
sampling can dictate changes in work practice and also allow the use of a
dust mask for comfort and not exposure control.
The larger concern is the fire and explosion hazard presented by the cleaning
operation. From your description, it appears that the worker is using
compressed air to blow the dust off the filters. Spray powder and paper dust
should never be blown off any surface. Suspending dust in air is dangerous
and if the conditions are right, can lead to a flash fire or explosion. The
safer practice is to vacuum spray powder and paper dust.
Graphic Arts Technical Foundation
200 Deer Run Road
Sewickley, PA 15143
412/741-6860 x608 - Phone
412/741-2311 - Fax