This is the text of the platform presentation.

1. FACILITY SURFACE DUST TALK
My presentation today is about facility surface dust (lead dust) from
soldering operations. This presentation does not deal with classic industrial
hygiene situations. Situations where employees are dealing directly with
hazardous chemicals, in this case, lead. My co-author, Mr. Dana Dickson
and I independently discovered this phenomenon of lead dust deposits with
its real and potential implications, and would like to share this information
with you.
ISSUES:
The general issue regarding lead dust deposits does not appear to be one of a
major health risk for building occupants. The issues are however important
and consist of the following:
• Potential property transfer liability
• Potential health risk for building maintenance personnel
• Potential health risk for susceptible populations
• Risk of lead exposure to building occupants
Potential Property Transfer Liability
When building are purchased, the buyer wants to minimize liability. If
soldering operations deposit lead on surfaces, especially in excess of some
guideline (e.g. HUD) then the possibility of transfer liability is real.
Building Maintenance Personnel
Surface lead concentration levels we have found (independently) in
ductwork and on ventilation equipment surfaces and filters have been orders
of magnitude higher (milligrams per square foot vs. micrograms per square
foot) than HUD standards. This was true for both HVAC systems and local
exhaust systems. It is possible that maintenance personnel could have lead
exposure in a previously contaminated building. In a building currently
using lead, maintenance personnel could also be exposed to lead dust many
hundreds of feet away from the soldering operations.
Potential Health Risk for Susceptible Populations
An example of a worst case scenario would be if a contaminated facility
were converted into a day care center, health facility or school.

2. Risk of Unnecessary Lead Exposure to Building Occupants
If the contamination is there then the potential risk of exposure is greater.
To eliminate the chance for exposure, either eliminate the contamination or
eliminate contact with contaminated surfaces. This is a principle of
industrial hygiene.
While I’m on the subject of IH principles let’s discuss some of our classic
rules…. (Slide 3)
Mr. McDermott states that, if exposures are less than acceptable levels, you
have basically done your job. The first sentence in this slide (Slide 4) also
states one of our basic IH principles – No (significant) worker exposure
implies no hazard further away. Does this rule of thumb work most of the
time? – yes, but not necessarily when it comes to lead fume and surface
contamination issues. Why doesn’t it work with lead and contamination
issues?
FAN VOLUME VS IH SAMPLE VOLUME:
First, when you think about it, personal sampling volumes for lead are small
in comparison to HVAC air volumes. We would sample 960 liters of air (34
cubic feet of air) for an 8-hour sample at 2 lpm. Think about the hundreds
and even thousands of cubic feet of air per minute going through general
ventilation systems. Think for a moment – if the lead fume has any
tendency for settling on surfaces, how little the air concentration would have
to be to have significant surface contamination given months and years of air
circulation in the facility.
FATE OF FUME:
What surprised me on my first experience with lead surface dust was the fact
that the airborne lead fume not captured by the local exhaust would settle on
surfaces. We know that lead fume is very small and I thought that even if a
minute amount of lead fume escaped the local exhaust and circulated in the
general ventilation most of the fume would leave the building. Measurable
concentrations of lead are deposited on surfaces throughout the building.
SURFACE LEAD STANDARDS
Let us discuss some surface lead standards. HUD Standards (Housing
Urban Development Standards) are 100 ug/ft2 for floor and carpet, 500 ug/ft2
for window sills and 800 ug/ft2 for window wells. NIOSH in a 1994 case

3. study article in Applied Occupational Hygiene proposed 46 micrograms per
square foot as their level of concern. NIOSH also stated they considered this
level to be too conservative after analyzing their data. There are no
published regulatory or consensus standards for industrial surface lead
contamination.
Over the past few years hygienists in our area, have considered 200-300
ug/ft2 of lead as non-hazardous surface concentration. This criteria is
loosely based on the HUD standards. The criteria also considers the
characteristics of the population at risk and what has been found to be a
feasible cleanup level.
This slide is a wave solder machine. The machine uses a wave of molten
solder to solder multiple components onto a printed circuit board. This slide
shows hand soldering. We all know that personal airborne lead exposure
from hand soldering is minimal. However, we have found evidence that if
given enough time, hand soldering can contaminate facility surfaces with
lead.
SAMPLING DATA:
Facility A – Wave Solder
Facility A is a printed circuit board manufacturing and assembly operation.
As you can see air samples in the immediate work place are less than the
PEL of 50 ug/M3. Blood tests of the maintenance personnel that clean and
maintain the wave solder machine have blood lead results less than the
OSHA standard and less than the state health department standard.
However look at facility A’s surface lead concentration data:
Operator workstation and assembly workstations are relatively clean,
because the surfaces are cleaned regularly as per OSHA mandate. The
surfaces away from the operator are however much more contaminated.
FACILITY B
Facility B is a warehouse/office facility that last had hand and wave
soldering operations more than 11 years ago. While the majority of samples
were less than 200 ug/sq. ft., three samples were 800-999 ug/sq.ft, and three
samples were found to have milligram per sq. ft. concentrations.

4. FACILITY C
Facility C is a wave soldering and hand soldering facility in which
approximately 50% of the first floor of the two story building was engaged
in the lead operation. The building was undergoing ownership transfer and
we were asked to do a 30 sample surface testing survey on the remaining
ventilation systems. Most of the sample results were in milligram/sq. ft.
concentrations. These data include samples from general and local exhaust
systems. Carpet close to the wave soldering operation did not pass TCLP.
The lead not captured by local exhaust was recirculated through a ceiling
plenum, and as a result, the plenum surfaces.(eg: ceiling panels electrical
fixtures etc.) were all thought to be contaminated. Before we could sample
other surfaces, we were told not to continue sampling. It was interesting to
note that while we were taking our lead samples the upper floor was being
remodeled. The interesting item of note is that the wave soldering operation
on the first floor used to be on the second floor for many years.
FACILITY D
Facility D is a large facility in which hand soldering and sand blasting is
done. The two samples in the 200-499ug. range were in the electronics
repair shop, while the higher sample was in the radiator shop. Sandblasting
of lead painted casting had be done in the facility, but not in either of these
areas. Although the sample number is small these data imply that hand
soldering, can contaminate facility surfaces.
DISCUSSION
We have seen four facilities with various levels of lead contamination. Now
lets look at some pre-clean/post-clean data to see if our claim of surface lead
contamination less that 200-300 ug/sq.ft. can be attained . As you can see in
the case of the Facility A HVAC system most of the postclean surfaces had
wipe sample results of less than 100 ug/sq.ft. Two samples were found to be
over 200ug/sq.ft. after the “initial” cleaning. The areas were re-cleaned and
passed the 200 ug/sq.ft. criteria.
There has been a legal case that has looked at lead contamination liability.

5. The BCW Associates Ltd. and Knoll International Inc. vs. Occidental
Chemical Corp and Firestone Tire and Rubber Company.
September 29,1988
U.S. District Court for the Eastern District of Pennsylvania
Civil Action No. 86-5947
The plaintiffs sought to recover costs related to cleanup of lead dust from a
warehouse in Pottstown, Pennsylvania pursuant to the CERCLA act of 1980.
The court determined the plaintiff knew it had purchased a dusty warehouse
(as is) but had no suspicion that the dust (which was mostly zinc oxide) had
lead sulfate contamination. The zinc oxide was originally used to make
white sidewall tires. The plaintiff upon discovering the lead sulfate provided
employees with PPE and also stated that the dust was contaminating
furniture that it was manufacturing.
The plaintiffs sought to receive compensation for:
Sampling and testing
Personal protective equipment
Cleanup and removal of contamination
Legal fees
The court said that if the defendant had acted responsibly and carefully
collected all the dust generated by the tire grinding operation and disposed
of it in an appropriate facility and if the dust had been released into the
environment Firestone would be liable under CERCLA.
The court went on to say that the defendant could not circumvent the
liability by allowing the lead to remain in the warehouse, and then released
into the environment.
In its defense the defendant contended that the plaintiffs were motivated not
by CERCLA liability in initiating clean up, but by product liability, quality
control and employee health. The court said that the defendant confused
causation with motivation.
The facts in this case are different than the facts surrounding soldering dust
contamination. The plaintiff claimed that the furniture it was making was
contaminated, and thus contaminating the environment. Nevertheless, this
case appears relevant.

6. I have discussed data on lead contaminated surfaces in facilities and some
implications of the contamination. Are there things we could do to minimize
lead accumulation and associated liability?
YES.
The industrial hygiene principles of substitution, other engineering and
administrative controls, and education are applicable to the control of this
potential hazard.
Keith/leadpresentation98.doc