Use in Foam Blowing

is being evaluated as a blowing agent in a variety of thermoset foam 

applications. 

Blowing agent end uses include: 

Rigid Polyurethane: Appliance foam includes insulation foam in domestic refrigerators 

and freezers. 

Rigid Polyurethane: Spray, Commercial Refrigeration and Sandwich Panels includes 

insulation for roofing, wall, pipes, metal doors, vending machines, coolers, buoyancy, 

and refrigerated transport vehicles. 

Polyurethane: Extruded Sheet includes foam for buoyancy or flotation. 

Rigid Polyurethane: Slabstock and Other includes insulation for panels and pipes. 

Rigid Polyurethane & Polyisocyanurate Laminated Boardstock includes insulation for 

roofing and walls. 

Phenolic Insulation Board & Bunstock includes insulation for roofing and walls. 

Estimates of worker exposure to a new chemical substance can be made based upon a 

general knowledge of the processes used and the work practices employed. It is important 

to understand that in foam applications, although the blowing agent is added neat to a 

blend tank, it is not processed neat in the foam reaction but as part of a raw material 

blend (B-side). The blend contains various other components. This blend is mixed with 

diisocyanates (A-side) in foam processing equipment and then poured or sprayed into a 

mold, free-rise conveyer system, cavity, wall or roof surface and the resulting polymer 

foam material is allowed to cure. The blowing agent becomes trapped in the cells of the 

foam as it cures, thus giving the foam insulating properties and limiting the amount of the 

chemical in the surrounding environment. Typical foam manufacturing lines employ 

from 3-9 people, each with varying degrees of potential exposure to the new chemical 

substance. In a traditional spray foam application there are 2-4 people in the immediate 

vicinity of the spray application all of whom are wearing respiratory PPE. All sites using 

the blowing agent employ engineering, industrial hygiene and personal protective 

controls to strictly limit worker and environmental exposure to the diisocyanates and 

other components of the foam mixture. These controls will automatically limit the 

potential worker exposure to the blowing agent. 

Any foam which currently uses HFC-245fa as the blowing agent is a potential application 

for We have not measured emissions during its use in blowing 

agent applications because the sufficient quantities with which to carry out significant 

commercial scale trials have not yet been produced. However, in the course of Product 

Stewardship and R&D for HFC-245fa, air sampling was conducted at some 

representative customer sites to determine levels of HFC-245fa at various workstations 

during full scale polyurethane foam manufacturing operations. We believe that HFC245fa is an acceptable surrogate for due to its similar physical property 

characteristics, most notably its boiling point, vapor pressure and heat of vaporization. 

Reference: Table X 
Table X: Comparison of Physical Properties 

 HFC-245fa 

Boiling Point, oF 66 62.4 

Vapor Pressure, PSIA @ 68 oF 16 18 

Heat of Vaporization, Btu/lb at bp 83.4 84.6 

 

Attachment 1 contains the results of the HFC-245fa emissions measurements. Both area 

and personnel exposure data were collected during roofing and wall spray foam 

applications; as well as area samples and personnel exposure data during appliance, pour 

in place, bunstock and boardstock manufacturing trials. The area and personnel exposure 

samples were collected via one of 3 procedures depending upon location and HFC-245fa 

concentration: via evacuated air cans and later analyzed by GC, via a Model R1-413 

halocarbon Indicator manufactured by GASTECH, Inc., and a Assay Technology passive 

dosimeter. 

When reviewing the monitoring data, it is important to realize that many samples were 

taken at vent holes and other locations where it would be impossible for workers to be 

present, i.e. inside hoods or at the end of lines beneath large vents. These sampling 

points were chosen to determine worst case levels at the points where the greatest 

concentrations are typically expected. Levels at locations where workers are typically 

situated without PPE are expected to be less than 10 ppm. It should be noted that the 

highest levels recorded occurred near the applicator during spraying of polyurethane wall 

foam in a home under construction. During this work, entry into the application area is 

restricted to only personnel wearing appropriate PPE. Higher levels were also found at a 

research and development facility. Neither of these locations is set up with the same 

sophistication and standard engineering controls that exist in a commercial facility. 

In all applications and job functions, based upon the physical properties of the new 

chemical, actual exposure is expected to be equivalent to what is seen with HFC-245fa 

systems. 

The number of sites at which will be processed and used for test marketing is 

uncertain but will be limited to those customers who have completed confidentiality 

agreements. We anticipate the number of sites to be approximately 100. All sites will be 

industrial facilities, commercial facilities or polyurethane spray foam sites utilizing HSE 

trained applicators. These are sites and applicators that have been using similar 

fluorocarbons in these applications for a number of years. Since the properties of 

 do not differ substantially from those of fluorocarbons historically used, 

adaptation of these manufacturing and application processes to the new blowing agent 

should not pose any special difficulties. This has been demonstrated with initial proof of 

concept foam testing. (Reference paper Bowman, et. al. and Bogdan, et. al.) Due to the 

similarity in physical properties of to HFC-245fa it is logical to believe that 

there would be comparable emissions and therefore exposure scenarios under the same 

processing conditions. Therefore, we do not expect exposure scenarios to be any 

different than those of similar fluorocarbons on the market today and believe there will be 
no problem in maintaining a worker level well below the Honeywell temporary 

Occupational Exposure Limit (OEL) of 500ppm. 

exhibits desirable environmental properties. The GWP of is much 

lower than that of HFC-245fa. has an atmospheric lifetime of 26 days and a 

Global Warming Potential of 7. An increasingly important environmental property is 

photochemical reactivity, i.e., participation in the reactions that generate ground-level 

ozone and other components of photochemical smog. Control of Volatile Organic 

Compound (VOC) emissions from industrial processes and products is mandated at both 

the federal and state levels. A petition will be filed to exempt from the 

definition of VOC on the basis that exhibits very low photochemical 

reactivity. 

Finally, it should be noted that is considered to exhibit only a low order of 

toxicity. Based on review of toxicity test results to date, Honeywell has set a temporary 

Occupational Exposure Limit (OEL) of 500ppm. This value will be reevaluated after the 

final results from ongoing toxicology testing are reviewed. The temporary value is 

significantly higher than the PELs assigned to many currently used blowing agents and is 

considered to be a very useful property of a blowing agent.