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Subject: Isocyanate testing during Spray Roof Application at Whitehouse, OH

April 29 & May 4, 2009

Executive Summary

Industrial hygiene air monitoring was conducted at the BASF Whitehouse, OH facility on 

April 29 and May 4, 2009 to assess airborne concentrations of MDI and TDI during 

application of a spray roof system.

Testing was performed during MDI-based polyurethane spray foam installation and 

application of three spray top coatings: Sonoguard® Basecoat, Neoguard Permathane®

Topcoat – White Trial (70613F) and Neoguard Permaguard® FR High Build – Black Trial 

(7419F). The three coatings were identified as containing up to 0.1% TDI.

Results from the monitoring indicate

• Personal exposure to MDI during the polyurethane foam application was 34% of the

OSHA ceiling limit of 20 ppb.

• Personal exposures to TDI based top coatings were non-detectable.

• Area samples for MDI and TDI taken downwind at ground-level were all nondetectable.

Recommendations

• The personal protective equipment protocols in use at the time by the sprayer were 

appropriate for isocyanate protection and should be continued. Others on the roof 

near the spray operation should follow similar protocols.

• Conduct additional sampling to evaluate TDI exposure when spraying the 

 Topcoat - WhiteNe Coating (70612A) and repeat sampling for the four coatings to 

increase statistical validity of the dataset.

• Conduct sampling to evaluate solvent emissions from spray coat systems.

• Advise facility maintenance engineers to close off air intakes and exhausts 

necessary to prevent vapors from being drawn into building.

BASF Corporation

1609 Biddle Avenue

Wyandotte, MI 48192-3729

Tel: (734) 324-6000 

www.basf.com/usa
BASF Corporation

1609 Biddle Avenue

Wyandotte, MI 48192-3729

Tel: (734) 324-6000 

www.basf.com/usa

Introduction and Scope

At the request of Terry McGee, Marketing Manager for BASF Polyurethane Foam 

Enterprises (BPFE), isocyanate exposure assessment was conducted during a spray 

roofing system application that included an MDI-based spray foam and top spray coatings 

containing up to 0.1% TDI.

Personal breathing zone samples were taken of the spray applicator while area samples 

were taken directly downwind at ground level approximately 30 feet from the building.

Site Conditions

The R&D facility shut off air intakes and exhausts near the spray area and closed the 

parking lot to the south which was generally downwind. Otherwise, normal operations were 

conducted.

The weather conditions on day one included light rain in the morning with clearing by late 

afternoon. Winds ranged from 5 – 15 mph in the early afternoon to less than 5 mph in the 

evening. Sampling during polyurethane foam application occurred in the afternoon while 

the Base Coat coating tests occurred in the evening when the winds had calmed.

The weather conditions on day two were sunny with winds ranging from 5 – 15 mph in the 

early afternoon to less than 5 mph in the evening. Topcoat and High Build 

testing also occurred in the evening when the winds had calmed and temperature were 

above 60oF.

Regulated Limits

The Occupational Safety & Health Administration (OSHA) specifies a ceiling limit of 20 

parts per billion (ppb) for both isocyanates while the American Conference of

Governmental Industrial Hygienists (ACGIH) has established a Threshold Limit Value (TLV)

for both isocyanates of 5 ppb as an 8-hour Time-Weighted Average (TWA).

Methodology

Sampling was performed using SKC AirCheck Hi-Flow pumps to collect personal breathing 

zone and area samples of isocyanate aerosol and vapor. The pumps were calibrated to a 

flow-rate of approximately 1.0 L/minute using a BIOS dry piston calibrator. The average 

flowrate before and after sampling was used to calculate air volumes.

The samples were collected on 13 mm glass fiber filters impregnated with 1-(2-pyridyl) 

piperazine (1,2 PP). As soon as a sample was collected, the filter was removed from the 

cassette with tweezers and placed in a vial containing two milliliters of a solution containing

90% acetonitrile and 10% dimethylsulfoxide.
BASF Corporation

1609 Biddle Avenue

Wyandotte, MI 48192-3729

Tel: (734) 324-6000 

www.basf.com/usa

The vials along with a blank filter in a vial of solution were shipped to the BASF lab in 

Wyandotte, Michigan. The samples were analyzed using a modified version of OSHA 

Method 47 at this American Industrial Hygiene Association (AIHA) accredited laboratory. 

The concentrations reported in ppb include the vapor and aerosol form of the isocyanates.

Observations

1) Solvent odors were evident on the roof, inside the R&D building and downwind 

outside the building during spraying. A slight negative pressure relative to outdoors 

existed inside the building.

2) Solvent thinning of the coatings using xylene was performed. Grounding and 

bonding of solvent transfer equipment was lacking.

3) Roofing personnel working near the spray applicator did not follow same PPE 

protocol as the spray applicator. Wind direction occasionally shifted and roof 

equipment (HVAC, etc.) created turbulent wind currents.

Results

The MDI result for the sprayer while applying the MDI-based urethane foam was below the 

OSHA ceiling limit of 20 ppb. The area sample taken approximately 30 feet downwind was 

non-detect. Continuous spraying over an entire shift could result in a sprayer exposure at

or above the ACGIH TLV of 5 ppb. The sprayer used appropriate PPE to prevent overexposure to MDI.

Table 1: MDI Results

Sample ID Date Type Material Sprayed Result (ppb)

0429-MFA 04/29/09 Area MDI-based Urethane Foam *ND @ 0.22 ppb

0429-MF-SR 04/29/09 Personal MDI-based Urethane Foam 6.8

All TDI results were below detection limits.

Table 2: TDI Results

Sample ID Date Type Material Sprayed 2,4 TDI 

Result (ppb)

2,6 TDI 

Result (ppb)

0429SA 04/29/09 Area Sonoguard® Spray Coat ND @ 0.21 ND @ 0.53

0429SP-DH 04/29/09 Personal Sonoguard® Spray Coat ND @ 0.32 ND @ 0.81

0504NEOW-A 05/04/09 Area Neoguard Permathane® White ND @ 0.40 ND @ 0.99

0504NEOW-DH 05/04/09 Personal Neoguard Permathane® White ND @ 0.43 ND @ 1.1

0504NEOB-A 05/04/09 Area Neoguard Permaguard® Black ND @ 0.49 ND @ 1.2

0504NEOB-DH 05/04/09 Personal Neoguard Permaguard® Black ND @ 0.42 ND @ 1.1

*ND = Not Detected at specified detection limit.
BASF Corporation

1609 Biddle Avenue

Wyandotte, MI 48192-3729

Tel: (734) 324-6000 

www.basf.com/usa

Conclusions and Recommendations

1) The results indicate TDI was not detectable when applying any of the top spray 

coatings containing 0.1% TDI.

2) The MDI concentrations encountered by the sprayer when applying the 

polyurethane foam was 34% of the Ceiling Limit, however, the TLV could be 

exceeded if continuous spraying occurred over an entire shift.

3) The personal protective equipment protocols in use at the time were appropriate for 

isocyanate protection and should continue. Others personnel on the roof near the 

spray operation should follow similar protocols.

4) It is recommended that additional sampling be conducted to evaluate TDI exposure 

when spraying the White Topcoat Coating (70612A) (which contains up to

0.39% TDI) and repeat sampling for all four coatings to increase statistical validity of 

the dataset.

5) It is also recommended that further evaluation of solvent emissions from spray coat 

systems be performed to determine nuisance, industrial hygiene, safety and 

environmental impacts related to solvent usage in these systems.

6) Instruction should be provided to building maintenance personnel regarding proper 

building pressurization and precautions necessary for air intakes and exhausts to 

prevent vapor entrainment during spray operations.

7) Grounding and bonding of solvent transfer should be initiated and enforced. It would 

be preferable that no solvent be added to the spray top coat formulations.