Low Pressure Spray Foam 

Products

Chris Bloom

Dow Chemical

February 15, 2012
2

Agenda

• Scope

• Objectives

• Overview of SPF Systems

• Key Application Areas 

• Exposure Monitoring Summary

• PPE Guidance

• Risk Profile Summary

• Product Stewardship Activity Summary

• Questions
3

Scope: Low Pressure SPF

2KLP

OCF

2KHP

Industrial

• One Component Foams or OCF

• Two Component Low Pressure 

Foams or 2KLP 
4

Objectives

• Enhance understanding of PU Chemistry as it relates 

to low pressure SPF products

• Provide a clear differentiation between SPF product 

types

– Review Phys-Chem attributes and delivery systems

– Review monitoring information

– Review PPE guidance

• Review the different ‘risk profiles’ associated with 

low pressure SPF products

• Provide an update on stewardship activities in the 

area of low pressure SPF products 
5

1-Component vs. 

2-Component Systems

• 1-Component:

– Isocyanate and Polyol combined in one container at time of 

manufacture

– Mixed at slightly greater than 1:1 into container

– Forms NCO-terminated PU in container

– 5-15% PMDI in container as marketed

– Reaction completed at time of application by reaction 

 with ambient moisture

– CO2 secondary blowing agent /propellant produced: 

• 2(R - N=C=O) + H2O ---> R-N-C-N-R + CO2

• 2-Component:

– Isocyanate and Polyol in separate containers

– Mixed 1:1 at time of application; 50% PMDI

Even if 

container is 

breached, only 

foam will be 

emitted
6

SPF Delivery Systems • Containers – Refillable Cylinders: • 2-component, Low-P only – Single-use Drums / 

Cylinders: • 2-component only, High

- & 

Low-P 

– Pressurized Cans / 

Single-use cylinders:

•1-component only
7

SPF Systems

For more available information, see the Spray Polyurethane Foam Health and Safety Website at www.spraypolyurethane.org. 
8

SPF Delivery Modes

• Spray

– 2-component only, high & low 

pressure

– Product application: 

insulation

• Stream / Bead

– 1-component & 2-component, 

low pressure only 

– Product application: adhesive, 

sealant 
9

SPF System Differentiation

• Basic Categories:

– High-Pressure SPF systems

• Designed for Industrial Use

• 2-component systems

• Applied at high temps and pressures

– Low-Pressure SPF products

• 2-component kits

• 1-component foam products

• Applied at ambient temps

Focus
10

Key Application Area for 

Low Pressure SPF Products

• Improve energy efficiency in residential 

and commercial structures

• Low pressure SPF products play a key role 

in addressing air sealing needs

– Rim joists

– Attics and crawl spaces

12

Low Pressure Worker 

Exposure Monitoring

• Species monitored: 

– MDI

– MDI & main oligomer (“3-ring”, n=1)

• Occupational Exposure Guidelines

– OSHA: 200 mg/m3 MDI (20 ppb; ceiling)

– ACGIH TLV®: 51 mg/m3 MDI (5 ppb; 8-h TWA)
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Monitoring Summary 

• Both 1- and 2- component low pressure foam 

products have significantly (~10x) lower worker MDI 

exposure profiles than high pressure foam systems.

• 1-component foam products have significantly lower 

exposure profiles than 2-component low pressure 

kits.

• Current PPE guidance for 1- and 2- component low 

pressure foam products provides adequate 

protection.

• Ongoing opportunity to provide enhanced outreach 

and education to end users regarding safe use and 

handling techniques. 
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Applicability to 

Consumer Related End Uses

• Low-pressure products studied were:

– Representative of products for use in homes (2-

component single-use kits) by weatherization 

professionals 

– Representative of extreme-case consumer use (1-

component foams)

• Professional products (single-use cylinders) used 

in exposure studies had higher PMDI content than 

consumer cans (13-15% vs. 6-11%)

• More material applied during sampling

• Respirator use not necessary for typical 1-

component applications.
15

Exposure Study Using Low Pressure 

SPF on Weatherization Jobsite 

• Actual weatherization job in Connecticut; May, 2011

» Conducted by independent BPI-certified building analyst

» Independent lab for MDI monitoring (OSHA 4247)

• Job scope

» Air seal attic, rim joist in basement with LP SPF

» Mechanical ventilation applied, respirators used, temps & 

humidity recorded

• Results

» No recorded airborne levels of MDI in work areas during and after 

foam application, applicator levels well under permissible limits 

» No MDI detected after 1 hour in attic, 2nd, and 1st floor
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PPE Guidance for Applicators and Helpers
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General Risk Profile Comparison for 

OCF and 2KLP SPF Products 

OCF

2KLP

(bead)

2KLP

(spray)

Risk = Hazard x Exposure

Exposure

Potential

PPE Sophistication
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Product Stewardship Activities

• spraypolyurethane.org website (Nov 10 – Jan 12) 

– Total Visitors: 48,572

– Total Page Views: 249,629

• Enhanced user friendly information on safety 

considerations when using OCF products

• Enhanced product labeling for 2K kits

• 2KLP application video (May 1,2011 – Feb 8, 2012)

– Page Views: 920

– Downloads of zip file of video: 59

– Youtube Views: 635

• Online training course for 2KLP foam application 

slated for Fall 2012 
APPENDIX 
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Sampler Types

– Coated Filter

– Impinger

– Impinger + filter
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Iso Check Sampler
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Impinger / Filter Comparison

• Side-by-side sampling done in Study 

2 (2-component low pressure SPF exposure 

study)

• 5 data points; Results: 

– Mean Impinger / Filter ratio = 1.7

– Range: 1.1 – 2.8
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Low-Pressure Spray Foam Worker 

MDI Exposures

5 studies, 41 personal (task) samples, 68 area / source 

samples

MDI Conc. (mean [range]; mg/m3)

2-component SPF 1-component SPF

Applicators 30 [ ND*(6) – 82 ] ND(6) [ ND(1) –ND(8) ]

Helpers 12 [ ND(6) – 36 ] n/a

Exposure 

Guidelines

200 (ceiling)

OSHA PEL

51 (8-h TWA)

TLV®

*ND() = not detected @ (detection limit), 1⁄2 

Detection Limit used for mean
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Exposure Studies: 2-Component 

Low-Pressure Kits

Study 1: Residential Wall Insulation Application (spray)

• Method: Impinger

Sample Type MDI mg/m3 Mean

[range]

n* #ND

Personal - Applicator 48 [16-82] 6 0

Personal – Helper

(3-10’ from Applicator)

16 [ND(6)-36] 6 1

Area – 15-30’ from 

Applicator

1.9 [ND(2)-4.1] 8 7

*n= # of samples; #ND = # of samples that were 

below limit of detection
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Low-Pressure SPF 

Exposure Study Details

• Lab application (4 studies)

– Spray onto cardboard / plastic

– In lab hood (fan off) or plant (general 

ventilation)

– Extreme-case simulation

• More foam applied over shorter period of time

• Source samples can be taken near point of 

application

• Application of insulation in home (1 

study)
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Exposure Studies: 2-Component 

Low-Pressure Kits (con’t)

Study 2: Lab Application; Area samples at hood entrance (fan off) 

• 3 different single use kits used; 7-15 min application

• Methods: Impinger w/ backup filter, Filter

Sample Type MDI mg/m3 Mean [range] n* #ND

Personal - Applicator 37 [13-66] 7 0

Area – Kit A (5 min use periods (3))

 Crack filler / sealer - bead

4.9 [ND(7)-9] 4 3

Area – Kit B (5 min use periods (3))

 Insulation – spray

55 [38-74] 3 0

Area – Kit C (full kit in 12 min)

 Insulation - spray

130 1 0

*n= # of samples; #ND = # of samples that were 

below limit of detection
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Exposure Studies: 2-Component 

Low-Pressure Kits (con’t)

Study 3: Lab Application 

• 2 different single use kits, 1 refillable 

system used

• 7-15 min application

• Area samples: 

– near (1-3’)

– far (10-20’)

• Method: Iso Check filter sampler

– Dual filter, MDI & oligomers
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Study 3 Results (con’t)

*n= # of samples; #ND = # of samples that 

were below limit of detection
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Exposure Studies: 1-Component 

Foam Products

Study 3,4,5: Lab Application 

• Adhesive, single use container; 11-24 min application

• Area samples at 1-20’, source (£ 18”)

• Methods: Filter sampler (Study 3: IsoCheck; Studies 4,5: 13mm)

*n= # of samples; #ND = # of samples that 

were below limit of detection

Sample Type MDI mg/m3; Mean [range] n* #ND

Personal -

Applicator

ND(6) [ND(1) –ND(8)] 11 11

Area: Near (1-3’)

 Far (10-20’)

ND(1) [olig=ND(6)] 

ND(0.9) [olig=ND(5)]

1

1

1

1

Area: Source 9.2 [ND(6) – 51] 15 13