Objective

Evaluate the potential exposure of workers to inhalable and respirable
polyurethane (PU) dust and pMDI during the post-application trimming /
cutting of half pound open cell & two pound sprayed PU foam insulation
(SPFI) in interior applications.  

Personal samples (within 30cm of the breathing zone) will be collected
for total inhalable particulates (TIP), respirable particulates (RP) &
pMDI on workers involved in cutting and trimming sprayed PU foam
insulation to evaluate worker exposure potential.

Source samples (within 30 cm of the area being trimmed and downwind of
it) will be collected for TIP to measure the maximum concentrations of
particulates produced by the trimming.

Sampling times will be as long as is reasonably practical (to increase
sensitivity) and will be representative of the work practices undertaken
by workers trimming sprayed PU foam insulation.

g/m3.

SPFI Trimming Experimental Procedure & Sampling Plan

The experiment will be carried out in an SPFI development laboratory
situation so that conditions can be controlled

No experiments will take place at least 24 hours before the experiment
in same room and no experiments will take place during the test which
could interfere with the tests.

Local exhaust ventilation will not be used.

Temperature, relative humidity, room air changes per hour, and room air
current direction in the vicinity of the trimming will be recorded.

The application and trimming operations will be videotaped for
documentation and explanation purposes

Area background (blank) samples (TIP, RP, pMDI) will be taken facing the
room air current a few meters away from the operation before the SPFI is
applied.

SPFI (a representative ½ lb or 2 lb formulation) will be applied to a
model wall section using normal commercial application techniques and
application rates.  The SPFI formulation and application conditions will
be chosen to produce foam with the highest potential to generate dust
(i.e., for closed cell foam, application will be a temperature below 70
degrees F). The SPFI will be applied in such a way that post-application
trimming will be needed. 

After a curing time of 1-2 hours, the foam will be trimmed using each
applicable trimming technique (see table below) for a total trimming
time of at least 15 minutes.  The duration of use of each technique will
be recorded.

Trimming Technique	½ lb (Open Cell) SPFI	2 lb (Closed Cell) SPFI

Foam Knife	X	n/a

Foam Planer	X	X

Grinder / Sander	n/a	X

Hand Scraper (e.g., putty knife, curry comb, ice spud)	X	X



A single personal sample of each type (TIP, RP, pMDI) will represent
composite exposure during all the trimming operations with the SPFI wall
section.

A single source sample (TIP) will represent composite particulate
concentration during all the trimming operations with the SPFI wall
section 

Steps 2 - 5 will be repeated with the same SPFI formulation as a
replicate. 

Steps 2 - 6 will be repeated with the remaining SPFI formulation.

Sampling & Analytical Methods

Particulates (TIP & RP)

TIP samples will be collected using IOM samplers equipped with
appropriate membrane filters.

RP samples will be collected using appropriate membrane filters equipped
with cyclonic pre-selectors operated at the flow rate to give the
appropriate cutpoint.

The concentration of particulate deposited on the filters will
determined gravimetrically using a microbalance.

Following the gravimetric determinations, the organic content of the
collected particulate will be determined by C, H & N measurements.

Particulate sampling will be carried out in accordance with
international standards, e.g.: 

ISO 15767:2009 - Workplace atmospheres. Controlling and characterizing
uncertainty in weighing collected aerosols 

MDHS 14/3 - General methods for sampling and gravimetric analysis of
respirable and inhalable dust.

CEN/TR 15230 - Workplace atmospheres - Guidance for sampling of
inhalable, thoracic and respirable aerosol fractions

Polymeric MDI (pMDI)

pMDI samples will be collected using 13-mm samplers equipped with binder
free GF filter impregnated with an appropriate derivatising reagent,
e.g., 1,2MP, 1,2-PP, or MAP

After sampling, filters will be immediately desorbed in the field and
returned to the laboratory for analysis.

All samples will be analysed for monomeric MDI and MDI trimer using
liquid chromatography   

pMDI sampling will be carried out in accordance with methods currently
used by MDI producers in the US. 

:  DUST & MDI MEASUREMENTS DURING TRIMMING OF SPRAYED POLYURETHANE FOAM
INSULATION

MS  AUTHOR    	Page   PAGE  1  of   NUMPAGES  2 	    12 Nov 2009

