[alt-photo] Re: lead white as ground

[Alberto Novo]

> Whenever lead is used in any way in which it can become airborne,
> the employer comes under the OSHA Lead Standard.  The employer is
> required to monitor the exposure of any potentially exposed employee
> during their use of the lead compound.  This includes teachers and
> even the janitor cleaning the area.

I would be cautious about the use of OSHA standards, because they refer to 
an exposure of 8 hours a day for a working life (PEL: Permissible Exposure 
Limit = 50 µg/m^3 averaged on 8 hours), or for limited times but still 
weighted (TWA: Time Weighted Average for that day, Maximum permissible limit 
in µg/m^3 = 400 divided by hours worked in the day).
I doubt that a conscious operator (that is, not spreading here and there, 
and playing with lead carbonate in a room) would reach those values in less 
than half an hour (TLW for 1 hour = 400 µg/m^3).
see 
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id 
=10030
(all the text in a row!) 

> Based on these air sampling tests in the breathing zones of the
> workers, the employer must create a written program detailing the
> precautions that will be used to insure that these exposures will be
> below the action limit for the standard of 0.03 mg/m3.  

0.03 mg/m3 is below the threshold for 8 hours! 

> ... I've seen scenarios like this
> before. 
> 
> I believe there is a separate occupational lead regulation in the
> Netherlands that has some of these features.

I would like to know more about this... 

Alberto
www.grupponamias.com
www.alternativephotography.com/wp/photographers/rodolfo-namias-group