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DHHS (NIOSH) Publication No. 2006–149

September 2006

SAFER • HEALTHIER • PEOPLETM
Preventing Asthma and Death from

MDI*

 Exposure During Spray-on Truck Bed Liner

and Related Applications

WARNING!

Workers exposed to MDI may develop serious or fatal respiratory disease.

Workers should take the following steps 

to protect themselves from MDI*

 exposure during spray-on applications:

1. Be informed.

■ Participate -

ing, 

training 

■ Know -

low -

facturers 

2. Use respirators and PPE safely.

■ Make 

respirators 

their 

■ Regularly 

parts 

respirators -

ness. 

hoses, 

■ When 

always -

pirator 

other 

wear -

ment 

chemical-resistant 

■ Never 

face -

tic 

visibility 

■ Be 

occur 

■ After -

moving -

tilation 

MDI.

■ Do 

has -

mum 

a -

ganic 

■ Know 

purifying 

the -

quately 

—

—

*

MDI 

 
Preventing Asthma and Death from 

MDI*

 Exposure During Spray-on Truck Bed 

and Related Applications

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WARNING!

Workers exposed to MDI may develop serious or fatal respiratory disease.

Workers should take the following steps 

to protect themselves from MDI*

 exposure during spray-on applications:

1. Be informed.

■ Participate in medical exams, medical monitoring, air monitoring, respiratory fit-testing, and

training programs offered by your employer.

■ Know the safety and health information and follow all safety precautions provided by the manufacturers about the product(s) you are spraying.

2. Use respirators and PPE safely.

■ Make sure that you have been fit-tested for your

respirators and that you have been trained in

their proper use, storage, and maintenance.

■ Regularly inspect and maintain all component

parts of supplied-air respirators and air-purifying

respirators to assure their continued effectiveness. The components include air compressors,

hoses, regulators, facepiece, etc.

■	 When	spraying	MDI,

always	use	a	full-facepiece,	supplie

pirator	 operated	 in	 a	 pressure-de

other	positive-pressure	mode	and

wear	appropriate	personal	protectiv

ment	 (PPE)	 (such	 as	 hooded	

chemical-resistant	gloves,	and	foot

■	 Never	remove	or	lift	the	respirator	away

face	while	in	the	spray	enclosure.	Use	c

tic	tear-away	sheets	on	the	visor	to	provi

visibility	throughout	the	spray	process.

■	 Be	 aware	 that	 the	 highest	 MDI	 conce

occur	inside	the spray enclosure.

■	 After spraying, leave the spray enclosure

moving your respirator and PPE and keep

tilation system running to exhaust any r

MDI.

■	 Do not re-enter the spray enclosure afte

has stopped without PPE and a respira

mum protection is an air-purifying respi

a full facepiece equipped with a combin

ganic vapor/N95 filter cartridge).

■	 Know the change-out schedule for

purifying respirator cartridge and stric

the schedule to make sure that you

quately protected from exposure to MD

—

—

*

MDI is methylenebis(phenyl isocyanate). In this fact

sheet, MDI refers to all MDI-based isocyanates.
Employers should take the following 

steps to protect workers from MDI exposure during spray-on applications: 

1. Provide workers who may be exposed 

to MDI with information and training 

about MDI as required by the OSHA hazard communication standard [29 CFR†

1910.1200].

■ Inform workers about the serious health effects 

that may result from exposure to MDI and provide them with safety and health information.

■ Inform workers about any materials that may 

contain or be contaminated with MDI. 

2. Provide respiratory protection and personal protective equipment to workers 

who may be exposed to MDI.

■ Develop, implement, and enforce a worksitespecific respiratory protection program that provides for medical monitoring, medical examinations, respirator fit-testing, and respirator training.

*

MDI is methylenebis(phenyl isocyonate). In this fact

 sheet, MDI refers to all MDI-based isocyanates.

†

Code of Federal Regulations.

■ Provide appropriate PPE (hooded coveralls, 

chemical-resistant gloves, and footwear) to workers who use spray guns and to other workers who 

may be exposed to MDI.

■ Train workers to properly use, store, and maintain their respirators.

■ Regularly inspect and maintain all component 

parts of supplied-air and air-purifying respirators 

to assure their continued effectiveness. The components include air compressors, hoses, regulators, facepieces, etc.

■ Make sure respirators are professionally fitted.

■ When workers must wear prescription eye glasses under a full-facepiece respirator, provide them 

with prescription inserts designed to be compatible with the respirator.

Supplied-air respirators 

■ When workers are spraying MDI or are inside the 

spray enclosure during spraying, make sure they use 

full-facepiece, supplied-air respirators operated in a 

pressure-demand or other positive-pressure mode.

■ Make sure that supply air for the supplied-air 

respirator is taken from a clean, uncontaminated 

area that is well removed from any aerosolized 

MDI or other contaminants. 

Preventing Asthma and Death from

MDI*

 Exposure During Spray-on Truck Bed Liner

and Related Applications

WARNING!

Workers exposed to MDI may develop serious or fatal respiratory disease.
Employers should take the following 

steps to protect workers from MDI exposure during spray-on applications: 

1. Provide workers who may be exposed 

to MDI with information and training 

about MDI as required by the OSHA hazard communication standard [29 CFR†

1910.1200].

■ Inform workers about the serious health effects 

that may result from exposure to MDI and provide them with safety and health information.

■ Inform workers about any materials that may 

contain or be contaminated with MDI. 

2. Provide respiratory protection and personal protective equipment to workers 

who may be exposed to MDI.

■ Develop, implement, and enforce a worksitespecific respiratory protection program that provides for medical monitoring, medical examinations, respirator fit-testing, and respirator training.

*

MDI is methylenebis(phenyl isocyonate). In this fact

 sheet, MDI refers to all MDI-based isocyanates.

†

Code of Federal Regulations.

■ Provide appropriate PPE (hooded 

chemical-resistant gloves, and footwe

ers who use spray guns and to other w

may be exposed to MDI.

■

coveralls, 

ar) to workorkers who 

and mainomponent 

 respirators 

. The comes, regula-

 fitted.

 eye glassovide them 

e compat-

 inside the 

re they use 

erated in a 

ure mode. 

upplied-air 

ntaminated 

aerosolized 

 Line

Train workers to properly use, store, 

tain their respirators.

■ Regularly inspect and maintain all c

parts of supplied-air and air-purifying

to assure their continued effectiveness

ponents include air compressors, hos

tors, facepieces, etc.

■ Make sure respirators are professionally

■ When workers must wear prescription

es under a full-facepiece respirator, pr

with prescription inserts designed to b

ible with the respirator.

Supplied-air respirators 

■ When workers are spraying MDI or are

spray enclosure during spraying, make su

full-facepiece, supplied-air respirators op

pressure-demand or other positive-press

■ Make sure that supply air for the s

respirator is taken from a clean, unco

area that is well removed from any 

MDI or other contaminants. 

Preventing Asthma and Death from 

MDI*

 Exposure During Spray-on Truck Bed r 

and Related Applications

WARNING!

Workers exposed to MDI may develop serious or fatal respiratory disease.
Preventing Asthma and Death from

MDI* Exposure During Spray-on

Truck Bed Liner and Related Applications

spray-on and related applications. Your assistance will help prevent asthma, other respiratory disease, and death.

BACKGROUND

Spray-on polyurethane/polyurea products 

containing isocyanates such as MDI have 

been developed for a wide range of retail, 

commercial, and industrial uses to protect 

cement, wood, fiberglass, steel, and aluminum surfaces such as truck beds, trailers, 

boats, foundations, and decks. MDI, toluene 

diisocyanate (TDI), and the polyisocyanate 

products based on the diisocyanate hexamethylene diisocyanate (HDI) are the most 

commonly used diisocyanates in the polyurethane industry. Isocyanates are widely 

used in the manufacture of flexible and rigid 

foams, fibers, coatings such as paints and 

varnishes, and elastomers. Isocyanates are 

increasingly used in the automobile industry, 

autobody repair, and building insulation materials. (See Appendix A for definitions and 

synonyms of MDI and information about its 

chemical structure.) 

WARNING!

Workers exposed to MDI* may develop serious or fatal respiratory disease.

The National Institute for Occupational 

Safety and Health (NIOSH) requests assistance in preventing asthma, other 

respiratory diseases, and death from 

exposure to methylenebis(phenyl isocyanate) (MDI). More than 10,000 U.S. 

workers are potentially exposed to MDI 

during spray-on truck bed lining operations. This Alert summarizes four case 

reports: one death and several incidents 

of asthma or other respiratory disease 

following exposure to MDI during sprayon truck bed lining operations. Information about preventing adverse health effects from exposure to MDI is urgently 

needed by workers, employers, small 

business owners, and physicians and 

other health care providers. 

NIOSH requests that editors of trade journals, safety and health officials, labor union 

leaders, educators, and MDI suppliers and 

manufacturers bring the recommendations 

in this Alert to the attention of all employers 

and workers at risk of MDI exposure through

*

MDI is methylenebis(phenyl isocyanate). In this alert, 

 MDI refers to all MDI-based isocyanates.
 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

Production and consumption data for the 

polyurethane industry in the United States 

and North America are available through 

the Alliance for the Polyurethanes Industry 

(API). Their publications End-Use Market 

Survey on the Polyurethane Industry [API 

2003] and Socio-Economic Impact of Polyurethanes in the United States [API 2004a] 

provide the following facts: 

■ In 2002, the U.S. market for polyurethane was 5,528 million pounds (87% 

of the North American market). 

■ The manufacture of products such as flexible slabstock, flexible molded foams, rigid foams, coatings, binders, elastomers, 

adhesives, sealants, reaction injection 

molding, thermoplastic polyurethanes, 

and spandex used 212 million pounds 

of MDI as a raw material and 1.3 billion 

pounds of polymeric MDI in 2002.

■ About 253,700 workers at 853 locations 

throughout the United States are employed in transportation industries that 

use polyurethane. Uses include resistant 

polyurethane coatings such as truck bed 

liners and other products such as headrests, armrests, adhesives, insulation, 

and other molded components used in 

vehicle production. 

Information gathered by a major spray-on 

truck bed liner company identified 17 companies that supply, distribute, and franchise 

spray-on truck bed lining equipment, materials, and products [Naik 2004]. Nationally, 

the number of spray-on truck bed liner businesses is estimated to exceed 2,000 [Lofgren et al. 2003]. Press releases from two of 

the major truck bed liner companies indicate 

that the spray-on bed liner industry is rapidly 

growing. Conservative estimates indicate that 

more than 10,000 workers are employed in 

the spray-on bed lining industry nationwide. 

Inspections by the Washington Industrial 

Safety and Health Administration (WISHA) 

of the Washington State Department of Labor and Industries at 13 spray-on truck bed 

lining businesses and a review of industrial 

insurance records found that workers are at 

risk of developing illnesses associated with 

diisocyanate exposure [Lofgren et al. 2003]. 

Seven of the 13 inspected worksites had 

MDI monomer air concentrations that were 

greater than the regulatory limit, resulting in 

regulatory citations. 

During their preparation of the report on inspections in Washington State, the authors 

contacted NIOSH and requested help with 

developing engineering controls and alerting 

affected employers and workers throughout the Nation. As a result, NIOSH began a 

study of the spray-on truck bed lining industry. NIOSH conducted walk-through surveys 

at spray-on truck bed liner facilities in Washington State, Colorado, Ohio, and Kentucky 

[NIOSH 2003a; Almaguer et al. 2004]. Six 

sampling surveys were conducted in Ohio 

and Kentucky. The results of the NIOSH 

sampling surveys are described later in this 

document. 

In 2003, Washington and Michigan actively 

began alerting the industry in their States of 

the hazards associated with spraying MDI in 

truck bed liner applications. In March 2003, 

WISHA issued a Hazard Alert warning of isocyanate exposures related to the spray-on 

truck bed lining industry [WISHA 2003]. The 

Michigan Occupational Safety and Health 

Act News described a fatality that occurred 

in Michigan during the application of an MDIbased spray-on bed liner to the interior of a 

van in February 2003 [MIOSHA 2003]. In 

December 2003, the Michigan Fatality and 

Control Evaluation (MIFACE) Program issued 

a report on the death, and the Michigan Occupational Safety and Health Administration 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications

(MIOSHA) issued an Alert in January 2004 

[MIFACE 2003, MIOSHA 2004]. In February 

2004, WISHA issued a Hazard Alert Update 

briefly discussing the Michigan death and 

the health hazards associated with exposure to isocyanates [WISHA 2004]. 

This Alert is intended to notify workers and 

employers in the truck bed lining and related industries of the adverse health effects 

associated with exposure to MDI during the 

application of spray-on truck bed liners. 

The current Alert also provides preliminary 

recommendations to reduce worker exposures to MDI during the spray-on bed liner 

process. 

SPRAY-ON TRUCK BED LINING 

PROCESS

The spray-on truck bed lining process involves applying a protective polyurethane or 

polyurea coating to the bed of pickup trucks 

or other vehicles and surfaces in a manner 

similar to undercoating. Bed liners are applied as a two-part resin. Part A is an MDIbased product; part B is usually a polyol or 

polyamine that reacts with the isocyanate to 

form a tough, resilient elastomeric surface 

coating. The MDI-based liners are applied 

to pickup truck beds and other surfaces to 

protect them from damage and to provide 

a nonskid surface. The spray-on application 

process is usually done in a spray enclosure. The spray-on truck bed lining process 

is commonly performed in spray-on truck 

bed specialty shops, auto body centers, and 

auto dealerships (see Figure 1).

NIOSH identified two spray-on processes 

commonly found in the industry [Heitbrink 

and Almaguer 2003]: one process applies 

truck bed liners at room temperature and 

pressures of approximately 50 pounds per 

square inch (low temperature/low pressure); 

a second process applies truck bed liners at 

temperatures above 165 °F and pressures 

of approximately 1,500 pounds per square 

inch (high temperature/high pressure). In 

both processes, the A and B components 

are pumped separately to the spray gun 

and mixed at the time of application. The 

worker uses a hand-held spray gun to apply the rapidly curing product onto the truck 

bed interior. The shape of the spray pattern 

is determined by the nozzle shape. To create a textured, nonslip surface on the bed, a 

small quantity of the coating is sprayed into 

the air, allowing the product to settle onto 

the truck bed. To obtain a bed liner thickness of 0.125–0.25 inches (a standard in 

the industry), approximately 50 pounds of 

the two-part resin (part A and part B) are 

sprayed onto the bed and inside walls of a 

typical pickup truck (see Figure 2). 

A third type of spray-on process that was 

not included in the NIOSH sampling surveys is the cold-batch, pre-mix process. The 

information contained in this Alert may apply 

to this process as well. During this process, 

isocyanate/resin and catalyst materials are 

Figure 1. Spraying base coat with protective equipment.
 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

generally mixed in small quantities (quarts 

or gallons) at room temperature with a 

high-speed drill. Afterwards, the mixture is 

poured into a hopper gun and applied at 

30–60 pounds per square inch from inside 

the truck bed. The chemicals used in the 

cold-batch operations typically contain less 

MDI (less than 20%). However, the coldbatch materials contain higher amounts of 

flammable solvents (toluene and N-butyl

acetate) which should have their own exposure prevention and ventilation requirements. 

Cold-batch systems are popular because of 

the lower startup costs [Krupinski 2005]. 

SPRAY APPLICATIONS OTHER 

THAN TRUCK BED LINING

Polyurethane and polyurea coatings are 

marketed and used for truck trailers, house 

decks, walls, foundations and sports flooring, and they are likely to be used for other 

applications as well. In many cases, these 

applications use the same or similar chemicals, spray techniques, and equipment as 

the spray-on truck bed lining process. Because of these similarities, excessive exposure to MDI may occur during these related 

applications, resulting in risk to spray gun 

users and other nearby workers. Owners 

and managers of these operations should 

assess and sample as necessary as well 

as implement needed controls and work 

practices, including engineering controls, 

worksite-specific respiratory protection programs, chemical hazard training, administrative controls, and use of personal protective 

equipment for exposed workers as outlined 

in this Alert [Lofgren et al. 2003]. 

HEALTH EFFECTS OF

ISOCYANATES

Isocyanates are the leading attributable 

chemical cause of occupational asthma in 

the United States and many other industrialized countries [Tarlo et al. 1997b]. Workers with asthma symptoms from isocyanate 

exposure often continue to have symptoms 

after exposures have been terminated. Affected workers often have to leave their jobs 

to prevent progression of respiratory symptoms. The major route of work-related exposure to MDI is inhalation of the vapor or 

aerosol.

Because the odor threshold for MDI is many 

times above the recommended exposure 

limit (REL), smell should never be relied on 

as an indication of exposure, nor should the 

absence of odor be used to indicate safety. 

MDI can be detected by odor only after dangerous concentrations exist, resulting in potential overexposure.

Exposure may also occur through skin contact during the handling of liquid MDI-based 

products. Work-related exposure normally 

Figure 2. Spraying texturizing coat with protective equipment.
MDI Exposure During Spray-on Truck Bed Liner and Related Applications

occurs during the spray application of MDIbased products. In 1996, NIOSH issued 

Preventing Asthma and Death from Isocyanate Exposure, which summarizes reported 

cases of disease and death following occupational exposure to diisocyanates and diisocyanate-based products [NIOSH 1996]. 

Irritation and Lung Injury

MDI and other isocyanates may irritate the 

mucous membranes of the eyes, upper and 

lower respiratory tracts, gastrointestinal tract, 

and skin [Swensson et al. 1955; Fisher 

1967; Upjohn Company 1970; Lofgren et 

al. 2003]. Eye tearing, nose and throat irritation, and cough may occur [Littorin et al. 

2000]. Respiratory irritation may progress to 

chronic upper and lower respiratory symptoms, although symptoms of local irritation 

do not reliably indicate chronic respiratory 

conditions [Wang and Petsonk 2004]. Acute 

respiratory distress syndrome or reactive airways dysfunction syndrome may also result 

from short-term high exposures [Tarlo et al. 

1997b; Banks 1998]. 

Respiratory Sensitization

Isocyanates can sensitize workers, making 

them subject to severe asthma attacks if 

they are exposed again, even when concentrations are continuously below the NIOSH 

REL [NIOSH 1973, 1978; Banks 1998]. 

Skin exposures may be associated with the 

onset of respiratory symptoms [Petsonk et 

al. 2000]. Respiratory disorders associated 

with isocyanate exposure include asthma 

and hypersensitivity pneumonitis [Baur et 

al. 1984; Baur 1995]. Sensitization may 

result from a single episode of overexposure 

or intermittent exposures at low concentrations. Once a worker is sensitized, even low 

concentrations may trigger symptoms such 

as wheezing, chest tightness, shortness of 

breath, and cough. Persons with chronic 

hypersensitivity pneumonitis may also experience fatigue and weight loss. These 

symptoms may begin immediately or may 

be delayed for up to 8 hours after exposure. 

Death from severe asthma in sensitized subjects has been reported [Fabbri et al. 1988; 

MIFACE 2003]. 

Carcinogenicity

Isocyanates may cause cancer in animals; 

however, evidence is insufficient to describe 

the carcinogenic potential of MDI in humans. Data from recent studies show that 

methylene dianiline (MDA), a known animal 

carcinogen and the principal metabolite of 

MDI monomer, is found in the blood of MDIexposed rats and in the urine of humans 

exposed to a mixture of polymeric MDI and 

MDI monomer [NIOSH 1986; Sepai et al. 

1995]. Another study found that a commercial grade of MDI (45% MDI monomer by 

weight) induced chromosome aberrations 

in human blood lymphocyte cultures after 

a 24-hour treatment [Mäki-Paakkenen and 

Norppa 1987]. NIOSH recommends that 

work-related exposure to MDI be minimized 

because of the potential for respiratory sensitization and the potential carcinogenicity 

of the metabolite MDA [NIOSH 1986]. 

CURRENT EXPOSURE LIMITS

Occupational exposure standards for MDI 

are based on respiratory irritation and sensitization. The available human evidence 

is insufficient to describe the carcinogenic 

potential of MDI [NIOSH 1989]. The evolution of the occupational exposure standards 

for isocyanates is discussed in the literature review Polyisocyanates in Occupational 
 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

Environments: A Critical Review of Exposure Limits and Metrics [Bello et al. 2004]. 

The isocyanate product frequently used in 

bed-liner formulations consists of varying 

amounts of MDI monomer and higher molecular weight species. Long-term aerosol 

inhalation studies suggest that monomeric 

MDI and polymeric MDI, which typically contain 50% monomer, have a similar response 

in rat lungs [Feron et al. 2001]. Mandatory 

and recommended limits have been established for MDI monomer, as discussed below. However, no recommended or regulatory limit exists for higher molecular weight 

species at this time. Therefore, regardless of 

the relative amount of MDI monomer present, owners and workers are encouraged to 

adhere to the control methods outlined in 

this Alert whenever MDI aerosols may be 

generated through a spray-on bed-lining operation. 

NIOSH

NIOSH recommends that MDI monomer exposure be limited to 0.05 milligram per cubic meter of air (mg/m3) or 0.005 part per 

million parts of air (0.005 ppm) as a timeweighted average (TWA) for up to a 10-hour 

workday during a 40-hour workweek, with 

a ceiling limit of 0.2 mg/m3 (0.02 ppm)

for any 10-minute period [NIOSH 1978]. 

This NIOSH REL is intended to prevent acute 

and chronic irritation and sensitization of 

workers but not to prevent health effects in 

workers who are already sensitized. Available data do not indicate a concentration 

at which MDI fails to produce adverse reactions in sensitized persons. Unless otherwise stated, use of the term NIOSH REL

in this document means the NIOSH REL of 

0.2 mg/m3 as a 10-minute ceiling concentration when referring to spray-on truck bed 

liner processes. 

OSHA

The current Occupational Safety and Health 

Administration (OSHA) permissible exposure 

limit (PEL) for MDI monomer is 0.2 mg/m3 as a 

ceiling limit (0.02 ppm) [29 CFR*

 1910.1000 

(a)(1)]. 

WORKPLACE EXPOSURE

ASSESSMENTS

Washington State 

In response to health concerns, Washington 

Industrial Safety and Health Administration 

(WISHA) inspectors conducted exposure assessments at 13 spray-on bedliner establishments [Lofgren et al. 2003]. Airborne 

concentrations of MDI monomer during the 

10- to 20-minute application process varied 

between shops and ranged from 0.045 to 

6.5 mg/m3. In 7 of the 13 shops, airborne 

concentrations of MDI monomer exceeded 

the State and OSHA ceiling limit of 0.2 mg/m3

. 

The method used for most samples consisted of an open-faced cassette having a filter 

treated with 1-(2-pyridyl) piperazine. WISHA 

concluded that conditions contributing to 

excess exposure included inadequate exhaust and make-up air, clogged ventilation 

filters, and a lack of training and awareness 

of the hazard. Workers who applied spray 

used either a supplied-air respirator or an 

air-purifying respirator with filter cartridge. 

Companies were cited for deficient respirators, inadequate respirator training programs, and lack of respirator fit-testing and 

engineering controls. Seven of the worksites 

with overexposure to MDI had one or more 

serious violations related to respirator use. 

*

Code of Federal Regulations. See CFR in references.
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

In addition, one establishment using a bedliner product containing a flammable solvent received a violation for the presence of 

sources of ignition in the spray area. 

NIOSH

The following summarizes MDI monomer 

exposure assessments from NIOSH surveys 

conducted at six spray-on truck bed liner 

sites. These exposure assessment sites included three surveys at low-temperature/

low-pressure operations and three surveys 

at high-temperature/high-pressure operations. Samples were collected in the spray 

enclosures during the bedliner application process, in truck preparation areas, in 

the office areas, and outdoors as close as 

practicable to the spray enclosure exhaust 

grill. Sampling was done for the duration of 

the process, which ranged from 16 to 43 

minutes in the spray enclosure. Longerduration sampling was done in areas outside 

the spray enclosure. The air samples were 

collected and analyzed using NIOSH Method 

5525 [isocyanates, total (MAP)], which uses 

1-(9-anthracenylmethyl)-piperazine (MAP) as 

the derivatizing reagent [NIOSH 2003b]. In 

accordance with the recommendations in 

NIOSH Method 5525 for sampling MDI aerosols, an impinger with MAP reagent solution 

followed by a MAP reagent-coated filter was 

used for collecting the air sample. The laboratory analysis of samples used high-performance liquid chromotography with ultraviolet absorbance/fluorescence detection.

Spray Enclosure 

The data from these six surveys show that the 

greatest risk for exposure occurs, as expected, in the spray enclosure. Airborne concentrations of MDI monomer were up to 27 times 

the NIOSH REL of 0.2 mg/m3 as a 10-minute 

ceiling concentration in the spray enclosure 

during the spray-on process. The geometric 

mean MDI monomer concentration in the 

spray enclosures at the low-temperature/

low-pressure process was 0.99 mg/m3, or 

approximately 5 times the NIOSH REL. The 

geometric mean MDI monomer concentration in the spray enclosures at the hightemperature/high-pressure process was 

0.78 mg/m3 or approximately 4 times the 

NIOSH REL. Nonmonomeric MDI was detected in the spray enclosure samples and 

ranged up to 42% of the total isocyanate 

group. All workers applying spray wore supplied-air, full-facepiece respirators, except 

for one who wore a supplied-air, half-facepiece respirator [Almaguer et al. 2004]. 

After the spray application process, postspray air samples were collected inside 

the spray enclosure. Eight of 12 post-spray 

samples showed low concentrations of MDI 

monomer; 4 of the 12 samples had nondetectable concentrations. These samples 

were typically 15- to 30-minute samples 

and ranged from below the limit of detection 

to 0.08 mg/m3. These results are averaged 

over the duration of the sample; concentrations immediately after spray application 

are expected to be higher and may require 

respiratory protection when re-entering the 

booth (usually to remove the vehicle) (see 

Recommendations). 

Truck Preparation Area

Airborne MDI monomer in the truck preparation area averaged 0.56% of that in the 

spray enclosure. Eight of the 12 samples 

taken in the truck preparation area were 

below the limit of detection. The four 

samples above the limit of detection had 

concentrations that ranged from 0.0057 

to 0.022 mg/m3. Unlike spray gun users, 

the workers in the truck preparation areas 
did not wear respirators designed to protect 

from exposure to MDI. The concentrations 

in the truck preparation area were below the 

NIOSH REL. However, detecting any MDI in 

the truck preparation area indicates that 

the spray enclosure was not under negative 

pressure as recommended. Because of the 

potential for worker sensitization to MDI, the 

spray enclosure should be maintained under 

a negative pressure to minimize the possibility that MDI monomer will escape from the 

spray enclosure to the truck preparation area 

or other adjacent work areas, and prevent 

worker sensitization.

Office Area 

In five of the six surveys, airborne MDI monomer in the office/lobby areas was below the 

limit of detection. Trace concentrations of 

MDI monomer (below the limit of quantitation) were detected in the office/lobby area 

of one shop. Again, this finding indicates 

that the spray enclosure was not under negative pressure as recommended, thereby 

presenting the potential for exposure to the 

office occupants. Placing the office/lobby 

areas as far as possible from the spray enclosure and exhaust areas minimizes possible exposure to MDI in these areas.

Exhaust Area 

Five of eleven outdoor samples for MDI 

monomer taken near the spray enclosure 

exhaust had concentrations greater than 

the limit of detection; the highest was 

0.41 mg/m3. These data indicate a potential for exposure to MDI in the exhaust area 

of the building, requiring restrictions as addressed in the Recommendations. 

Observations at the surveyed worksites suggest effective exhaust ventilation may have 

reduced MDI monomer concentrations in the 

spray enclosure during spray applications [Almaguer et al. 2004]. Only one site had an 

exhaust system designed to effectively capture contaiminants in the spray enclosure; at 

this site, airborne MDI was reduced to concentrations near the NIOSH REL. Airborne 

concentrations at 5 other sites with general 

exhaust ventilation were 3 to 27 times the 

NIOSH REL.

CASE REPORTS

The following case reports highlight examples of isocyanate-induced asthma, other 

respiratory disease, and death. 

Case 1—Spray-on Truck Bed

Lining (Fatal Asthma) 

A 45-year-old male worker with 1 year of 

tenure died from an acute asthma attack 

after spraying an MDI-based bed liner onto 

the floor and sides of a cargo van interior. 

The worker was wearing a half-mask, supplied-air respirator as well as latex gloves 

and coveralls. The spray area was defined 

only by “two curtains that could be pulled 

together to enclose the area and limit product overspray into the general shop area.” 

The room had no local exhaust ventilation. Room ventilation during the spray-on 

bedliner application was provided by raising the overhead door a few feet, opening 

the door near the rust-proofing area, and 

placing a box fan at this door to provide 

air circulation. After completing the job, the 

worker turned off the mixer for the spray-liner 

components (MDI and polyether polyol). He 

disconnected his airline from the respirator 

and walked around to the front of the building, where a coworker found him in acute 

respiratory distress. The coworker took him 

to a nearby urgent care facility where he developed cardiac arrest. He did not respond 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

to cardiopulmonary resuscitation. An ambulance took the worker to the local hospital 

emergency room where he was declared 

dead. After an autopsy, the county medical 

examiner stated that the worker had died of 

an “acute asthmatic reaction due to inhalation of chemicals.” 

In the past, the worker had tried to spray 

bed liners when customers and coworkers were not present because of the strong 

odors associated with the product. After the 

fatality, coworkers informed the owner that 

the victim said he had difficulty breathing 

after applying the bed liners and that he had 

used an inhaler. 

This fatality may have been caused by MDI 

sensitization. The spray area was enclosed 

with a curtain (not a permanent enclosure) 

and had no dedicated exhaust ventilation. 

The worker used a spray-gun and a halfmask, supplied-air respirator. Furthermore, 

the MIFACE report indicates that the worker 

told coworkers that he had had previous 

breathing difficulties after spraying bed liners and that he had used an inhaler in the 

past. This suggests that MDI sensitization 

probably occurred in the past and played a 

significant part in the fatality. The information reinforces the need for strict adherence 

to the recommendations in this Alert. 

Whether the worker knew that his past 

breathing problems were associated with 

his exposures at work was unclear, since he 

did not report them to the owner. No exposure assessment data are available for this 

fatality [MIFACE 2003; MIOSHA 2004]. 

Case 2—Spray-on Truck Bed

Lining (Asthma)

A 29-year-old male ex-smoker who worked 

spraying truck bed liners arrived at a hospital 

emergency room with complaints of chest 

discomfort and wheezing. He reported having been exposed to “fumes” generated 

during the application of MDI-based sprayon truck bed liners. He reported increasingly 

frequent episodes of shortness of breath 

and wheezing associated with exposure to 

isocyanates during 8 months of work at the 

truck bed lining company. The worker was 

diagnosed with asthma, treated with inhaled bronchodilators and intravenous steriods, and advised to see a pulmonologist. 

The emergency room record indicated that 

the physician failed to identify the isocyanate exposure reported by the worker as a 

possible etiology of the worker’s asthma 

[Bonauto and Lofgren 2004]. 

Case 3—Spray-on Truck Bed

Lining (Asthma)

A 30-year-old man developed rhinitis, a 

cough, wheezing, and shortness of breath 

4 months after starting work spraying truck 

bed liners. On one occasion, the worker reported to the emergency room but was not 

diagnosed with asthma. Symptoms persisted 

with daily episodes of shortness of breath, 

wheezing, and nausea. These symptoms occurred at midday after four to five bed liner 

applications. After 4 months of symptoms, 

which culminated in hospitalization for respiratory distress, the worker was diagnosed 

with work-related asthma from exposure to 

MDI. After hospitalization, the worker was 

documented to have nonspecific bronchial 

hyperreactivity by methacholine challenge 

testing. No inhalation challenge with MDI or 

workplace challenge testing was ever performed. The worker was removed from the 

workplace.

One year later, the worker was employed 

elsewhere as a manual laborer. He still had 
10 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

symptomatic asthma and was maintained 

on bronchodilators and inhaled steroids 

[Bonauto and Lofgren 2004]. 

Case 4—Spray-on Truck Bed

Lining (Asthma)

A 22-year-old worker who used a spray gun 

was employed in the truck bed lining industry for 18 months. He developed a runny 

nose and nasal congestion that occurred 

during the workweek but improved over the 

weekend. Increased breathing difficulty on 

exertion restricted his daily activities. The 

worker underwent a medical evaluation that 

included spirometry before and after the 

administration of bronchodilators. He was 

documented to have a reversible airflow limitation and was diagnosed with asthma. No 

workplace challenge testing was performed. 

The material safety data sheets (MSDSs) 

provided to the medical personnel revealed 

that the spray-on bed liner material consisted of 50% to 60% MDI monomer and 5% 

to 20% diisooctyl phthalate. The worker was 

removed from the workplace. 

A year and a half after medical removal from 

the workplace, the affected worker was still 

unemployed. He continued to have symptomatic asthma and was maintained on 

bronchodilators and steroid inhalers [Bonauto and Lofgren 2004].

CONCLUSIONS 

The cases described in this document reveal 

the potentially serious nature of respiratory 

disease resulting from exposures to MDI in 

the spray-on truck bed liner industry. Exposures may increase the risk of serious respiratory disease, respiratory sensitization, and 

death. MDI concentrations generated by the 

spray-on application of truck bed liners at 

the NIOSH exposure assessment sites routinely exceeded the NIOSH and OSHA ceiling limits and varied throughout the process 

with unpredictable, rapid increases in airborne concentrations. On the basis of these 

findings, NIOSH concludes that only a fullfacepiece, supplied-air respirator provides 

the necessary protection during MDI spray 

operations. 

RECOMMENDATIONS

Manufacturers and distributors of spray-on 

polyurethane/polyurea products containing MDI and other isocyanates should work 

together to assess and determine the best 

controls for the spray-on bed liner process. 

The ultimate goal is to establish procedures 

and develop controls (such as proper ventilation) to minimize MDI concentrations 

within the spray enclosures. These procedures and controls—together with respirator use, a written respiratory protection 

program, and ongoing worker training—will 

reduce the risk for worker exposures during 

the spray-on process. 

General Responsibilities for Shop 

Owners and Workers to Prevent 

MDI Exposures

■ Use any training, information, and literature available through the manufacturers, 

distributors, franchisers, and government 

agencies (see examples under manufacturer responsibilities).

■ Isolate the spray process by building an 

enclosure equipped with exhaust ventilation.

■ Use a pressure manometer or tracer 

smoke along cracks and walls to ensure that the spray enclosure is under 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 11

negative pressure and prevents the escape of MDI to adjacent work areas.

■ Use a full-facepiece, supplied-air respirator and wear personal protective clothing 

such as hooded coveralls, chemicalresistant gloves, and footwear to prevent 

dermal absorption during the spray application process. 

■ When entering or re-entering the enclosure immediately after spraying, use 

a full-facepiece, air-purifying respirator 

equipped with a combination N95 filter/

organic vapor cartridge as minimum protection and wear appropriate clothing to 

prevent dermal exposure.

■ To prevent fouling of the exhaust system 

and fan blades, filter all exhaust air at its 

collection point within the spray enclosure 

before it enters the exhaust system. 

■ Discharge exhaust from the spray 

enclosure away from occupied areas 

and ensure that the exhaust outlet 

is located away from HVAC air supply intakes and supplied-air respirator 

pumps/compressors. 

■ Ensure that only authorized persons 

trained in the use of safe work practices, ventilation, and personal protective equipment are allowed to perform 

spraying. 

General Responsibilities of 

Manufacturers, Distributors, and 

Franchisers of Spray-on Chemicals 

and Equipment 

■ Provide safety and health information to 

users of your chemicals and equipment. 

Include information about design of 

spray enclosures, engineering controls, 

safe work practices, and the hazards of 

exposure. These two references are excellent examples of useful information:

— MDI and TDI: Safety, Health and the 

Environment [Allport et al. 2003], 

by the International Isocyanate Institute Inc. for occupational safety and 

health information about MDI. 

— The API brochure Truck Bed Liners: 

Worker Protection, available in both 

English and Spanish. The brochure 

outlines safety precautions for spray 

gun users who apply spray-on truck 

bed liners [API 2004b]. The brochure 

is available through the API Web site 

at www.polyurethane.org.

■ Develop, publish, and distribute additional safety and health resources to help 

workers using spray-on MDI products. 

Detailed Recommendations

The following sections provide detailed recommendations for this industry, including further guidance about the choice of respirators 

and appropriate ventilation parameters. 

Product Substitution 

When feasible, substitute a less hazardous material for MDI and other isocyanates. 

NIOSH policy is always to recommend using a 

less toxic substitute if available. Water-borne 

acrylic coatings, polysulfide rubber coating, 

and epoxy are other chemicals that have 

been used to make truck bed liners. Dropin truck bed liners are also commercially 

available. NIOSH cannot address the quality 

or performance and has not addressed the 

safety of these products.

In addition, using substitute chemical processes or products may have advantages and 

disadvantages, including safety and health 

issues that are not addressed in this Alert. 
1 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

Equipment/Formulation Modification

■ Manufacturing and distribution: Investigate design changes that result in less 

aerosolization or fewer fugitive emissions 

during the spray process. 

■ Bed liner industry: Investigate potential 

process changes and work practices to 

determine whether reduced application 

pressure and slower application techniques result in lower MDI monomer air 

concentrations during the spray process. 

■ Chemical manufacturing: Consider changes in chemistry and formulation that would 

reduce the amount of fugitive MDI released 

during spraying. 

These design, process, and formulation changes could reduce airborne MDI, resulting in 

reduced worker exposures. They would also 

place less financial burden on retail owners 

and operators in controlling airborne contaminants during the spray process. Furthermore, 

less overspray would produce less waste and 

provide further economic benefit for the retail 

owner. Unverified evidence from a spray-on 

bed liner company suggests that using lower 

pressures (10 pounds per square inch) may 

reduce airborne MDI concentrations and thus 

lower the exposure. 

Spray Enclosure and Ventilation

Ventilation design (see Appendix B)

■ Design and build a spray enclosure to 

isolate the spray process and contain 

airborne MDI within the enclosure.

■ Minimize the size of enclosure to the 

smallest floor area and room volume 

compatible with the operation. This helps 

to maximize the efficiency of the ventilation system.

■ Equip the spray enclosure with an exhaust ventilation system to capture vapor and particulate MDI near the point of 

generation.

■ Ensure that the spray enclosure is under 

negative pressure to prevent leakage of 

airborne MDI into other areas within the 

shop. 

■ Provide clean “make-up” air to the spray 

enclosure to replenish exhausted contaminated air.

■ Place the make-up air supply and exhaust 

locations of this ventilation system so that 

the system generates a directed air (pushpull type) flow that maximizes ventilation 

efficiency and contaminant control. 

■ Discharge the exhaust high above the 

roof and away from air intakes, garage 

doors, or other openings where the exhaust could re-enter the shop. Also 

ensure that the exhaust is discharged 

above the roof recirculation region (See 

Industrial Ventilation: A Manual of Recommended Practice [ACGIH 2004] to 

determine the recirculation region). 

■ Control access to exhaust discharge areas 

by physical barriers and warning signs. 

Work practices

Spray gun users should be trained to make 

their work practices compatible with the 

control concepts of the ventilation system: 

■ Avoid standing between the spray nozzle and the ventilation system exhaust 

hood. 

■ Work with the spray nozzle downstream of 

the breathing zone, where the MDI contaminant will be diluted, directed away 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 13

from the breathing zone, and less likely 

to contribute to the worker’s exposure.

■ Allow the exhaust ventilation system to 

operate for an additional period at the 

end of spraying operations before deactivating the exhaust or allowing personnel to enter the spray enclosure without 

proper respiratory protection (see Respiratory Protection, page 14). This delay 

allows the ventilation system to purge 

or remove most remaining airborne contaminants. 

■ Do not enter exhaust discharge areas 

without respiratory protection. 

Ventilation system capabilities

■ Obtain a site-specific exposure assessment that includes sampling data at 

desired intervals following the spray operation. These data are the best way to 

determine the purge time (time required 

to reduce MDI concentrations consistently below the NIOSH REL) required for 

your ventilation system.

■ In the absence of exposure assessment 

data, determine the time required for the 

ventilation system to exhaust an air volume equal to a single room air change.

 ■ Calculate the required purge time, allowing sufficient time for at least three 

complete air exchanges—or even longer 

for systems with poor air mixing.

 ■ During the purge time, use respiratory protection when entering the spray enclosure 

(see Respiratory Protection, page 14).

■ For assistance calculating the time required for a single air change and the 

purge time of the ventilation system, see 

Appendix B. 

Ventilation maintenance

■ At least once per month, inspect and 

maintain the ventilation equipment to 

ensure adequate system performance 

(or more frequently if a decrease in performance is suspected).

■ Document and re-evaluate baseline ventilation performance measurements, including hood static pressure, pressure 

drop across filters, and velocity or volumetric flow measurements for indications 

of system performance degradation. 

■ Develop a maintenance schedule to 

change exhaust filters as needed to prevent reduced airflow. 

■ Ensure that exhaust fans have inspection access doors.

■ Ensure proper filter placement at air exhaust points to prevent filter bypass and 

the fouling of the exhaust system. 

■ Inspect fan blades regularly for material 

buildup and clean them to prevent a decrease in system performance. 

■ Check fan belts for deterioration and 

slippage and replace as necessary. 

■ Follow lock-out, tag-out procedures 

[29 CFR 1910.147] during inspection 

and maintenance procedures whenever 

worker injury may result from unexpected 

start-up of this equipment. 

Spraying in Enclosed Areas

■ Take additional precautions when spraying inside vans, enclosed trailers (e.g., 

horse trailers), and other similarly enclosed spaces.

■ Determine whether the area to be sprayed 

meets the definition of a confined space

and, if so, follow all OSHA requirements 
1 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

for working in a confined space [29 CFR 

1910.146].

■ Use supplemental local exhaust ventilation in addition to the exhaust ventilation 

of the spray enclosure. 

■ Wear a full-facepiece, supplied-air respirator and appropriate clothing to minimize the exposure. 

Worker Isolation

■ Restrict access to the spray enclosure to 

spray gun users.

■ Allow only essential workers wearing appropriate respiratory protection into the 

truck preparation areas or other areas 

where workers may be exposed to isocyanates. 

Exposure Monitoring

■ If you are a shop owner, conduct an exposure assessment for airborne MDI at 

the onset of business and any time a 

major change (structural or ventilation) 

is made to the spray enclosure. 

— Even if you install a ventilated enclosure design tested as effective 

for a product and process, conduct 

exposure monitoring to verify the effectiveness and proper installation at 

that site. 

— Ensure that spray gun users and the 

areas adjacent to the spray enclosures are sampled. 

— Use the appropriate sampling methods, as described in the NIOSH and 

OSHA analytical methods [NIOSH 

2003b, OSHA 1989]. 

■ Use the NIOSH REL of 0.2 mg/m3 as a 

10-minute or the OSHA PEL of 0.2 mg/m3

as a 15-minute ceiling limit concentration when interpreting exposure monitoring results. The short-term, intermittent 

nature of the spray-on truck bed liner 

process makes the NIOSH or OSHA ceiling limits the most appropriate exposure 

criteria for this process. Collect personal 

breathing zone samples from the time a 

spray operation begins to the time when 

spraying has stopped (typically a 10–20 

minute period). Compare results with the 

NIOSH or OSHA ceiling limit.

Additional assistance about managing this 

or other hazards can be obtained from the 

free, onsite OSHA consultation service in 

your State. For information about the OSHA 

Consultation Program, visit www.osha.gov/

dcsp/smallbusiness/consult.html or call 1–

800–321–OSHA (1–800–321–6742). 

Respiratory Protection

Typically, respirators should not be used as 

the primary control for routine operations 

except during situations such as implementation of engineering controls, some shortduration maintenance procedures, and emergencies. NIOSH exposure assessment data 

show that the engineering controls at the 

NIOSH survey sites did not reduce MDI concentrations below the occupational criteria, 

even at the sites with the best ventilation 

controls [Almaguer et al. 2004]. Airborne 

MDI monomer concentrations in the spray 

enclosures during the spray-on application 

process routinely exceed both the NIOSH 

10-minute ceiling limit (0.2 mg/m3) and the 

OSHA PEL as a 15-minute ceiling concentration (0.2 mg/m3). Therefore, NIOSH recommends the following respiratory protection for the spray-on truck bed liner industry. 

(See Appendix C for more information about 

respirators and respiratory protection.) 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 15

Use supplied-air respirators when 

spraying MDI

■ When spraying MDI-based products (including spray-on truck bed liners), use 

only supplied-air, NIOSH-certified respirators [42 CFR 84] with a full facepiece 

operated in a pressure-demand mode. 

MDI concentrations generated during 

the spraying process routinely exceed 

both the NIOSH and OSHA ceiling limits, 

even with engineering controls. NIOSH 

does not recommend air-purifying respirators for the spray-on truck bed-liner 

industry during the spray application, 

even though OSHA allows the use of airpurifying respirators for isocyanates under certain circumstances in accordance 

with the revised OSHA respiratory protection standard [29 CFR 1910.134(d)(1)(i) 

and 1910.134(d)(3)(iii)] (see the OSHA 

Standard Interpretations Letter dated 

07/18/2000 and titled Selection of Air 

Purifying Respirators for Gases and Vapors with Poor Warning Properties (Diisocyanates) [OSHA 2000]). 

■ While in the spray enclosure, do not lift 

or remove the respirator facepiece for 

any reason. 

■ If visibility is a problem during or after 

spraying, apply several tear-away layers 

of clear plastic film to the respirator visor 

before entering the booth. This would allow the worker to remove the top layer 

for increased visibility as needed during 

the spray-on process. 

Use air-purifying respirators for entry 

into the enclosure after spraying

■ To enter the spray enclosure after spraying is completed, use a full-facepiece, 

air-purifying respirator with an appropriate cartridge changeout schedule that 

is strictly enforced. NIOSH data indicate 

that MDI aerosol is still present in the air 

after spraying. An air-purifying respirator 

may be the most convenient and practical way to provide protection to workers 

needing to enter the spray enclosure 

after the spraying process is completed. A NIOSH-approved, full-facepiece, 

air-purifying respirator equipped with a 

combination organic vapor/N95 filter cartridge is the minimum acceptable protection necessary after spraying is complete 

and when no exposure assessment data 

or ventilation purge data are available. 

■ Use a full-facepiece to provide the necessary eye and dermal exposure protection.

■ Because MDI has inadequate warning 

properties (i.e., odor threshold) and is 

a potent sensitizer, follow a changeout 

schedule to ensure that the air-purifying 

respirator cartridge is replaced before saturation of the cartridge elements. Since 

MDI in this industry is principally an aerosol, equipping the air-purifying respirator 

with a particulate pre-filter element to 

protect the cartridge filter from premature clogging would extend the life of the 

more expensive filter/cartridge. 

■ Before re-entry, allow sufficient time for 

the ventilation system to remove airborne 

MDI (see Appendix B to calculate purge 

time). NIOSH exposure assessments determined that three air changes, combined with gravitational settling, was sufficient to reduce the MDI concentrations to 

less than 50% of the NIOSH ceiling limit 

at every sampled site (see Appendix B for 

details). 

Develop a respiratory protection program

■ Develop a written, site-specific respiratory protection program that, at a minimum, meets the requirements of the 
1 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

OSHA respiratory protection standard 

[29 CFR 1910.134] (See Appendix C).

■ Fully implement the respiratory protection program to protect spray gun users 

and any other workers who enter the 

spray enclosure. 

■ When respirators are needed to protect 

the health of the worker or when respirators are required by the employer, select 

a NIOSH-certified respirator based on 

(1) the respiratory hazards to which the 

worker is exposed and (2) workplace and 

user factors that affect respirator performance and reliability [29 CFR 1910.134 

(d)(1)(i) and (ii)]. 

■ Refer to the following publications for 

additional information about selection, 

fit-testing, use, storage, and cleaning of 

respiratory equipment: 

— NIOSH Guide to Industrial Respiratory Protection [NIOSH 1987] 

— NIOSH Respirator Selection Logic 

2004 [NIOSH 2004] www.cdc.gov/

niosh/docs/2005-100

— NIOSH Certified Equipment List (CEL). 

The CEL is a database of all certified respirators. It can be accessed 

at www.cdc.gov/niosh/npptl/topics/

respirators/CEL/default.html

The following links provide additional guidance for developing written respiratory protection programs:

— www.osha.gov/SLTC/respiratory

protection/index.html [OSHA 2004]

— www.polyurethane.org/pdfs/MRPP.pdf

[API 2001]

Personal Protective Clothing 

When spraying MDI-based products or during entry immediately after spraying, wear 

protective clothing such as hooded coveralls, 

chemical-resistant gloves, and footwear to 

protect the skin of the face, scalp, and neck 

areas from MDI aerosol as recommended 

in the publications Quick Selection Guide to 

Chemical Protective Clothing [Forsberg and 

Mansdorf 2003] and PMDI User Guidelines 

for Protective Clothing Selection [API 2002] 

(see Figure 3). 

Worker and Employer Education

Employers

Worker education is vital to an effective occupational safety and health program. To comply with the OSHA hazard communication

Figure 3. Worker wearing protective clothing and equipment.
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 1

standard [29 CFR 1910.1200], inform 

workers about the following: 

■ Methods and observations that may be 

used to detect the presence or release 

of a hazardous chemical in the work area 

(such as monitoring conducted by the 

employer, continuous monitoring devices, 

visual appearance or odor of hazardous 

chemicals when being released, etc.)

■ Physical and health hazards of the chemicals in the work area, including the likely 

physical symptoms or effects of overexposure

■ Protective measures, such as engineering controls, appropriate work practices, 

emergency procedures, and personal 

protective equipment

■ The details of the hazard communication program developed by the employer, 

including an explanation of the labeling 

system, the MSDSs, and means for workers to obtain and use the appropriate hazard information 

Workers and employers 

■ Use this Alert to facilitate chemical hazard training for workers spraying MDIbased products, including spray-on truck 

bed linings. 

■ Obtain MSDSs from suppliers or manufacturers. 

Chemical manufacturers and distributors 

■ Provide customers with information about 

the health effects of your products, including MSDSs and labels. 

■ Develop safe handling procedures for the 

chemicals and equipment used in the 

spraying of MDI-base products. Ensure 

that the end users are informed of these 

procedures. 

■ Provide easy-to-read information explaining the health effects of your products 

and steps to keep workers safe. Include 

safe handling brochures such as the API 

brochure Truck Bed Liner: Worker Protection [API 2004b]. The API brochure is a 

good example of manufacturers working 

cooperatively to improve worker safety by 

communicating important information in 

an easy-to-read format. 

Medical Monitoring 

■ Conduct preplacement examinations to 

obtain baseline health status. 

— Include all potentially exposed workers for the early detection and prevention of the acute and chronic effects of exposure to isocyanates. 

— Consult an occupational medicine 

physician who (1) has sufficient training and experience to recognize the 

adverse health effects of exposure 

to isocyanates and (2) is aware of 

the control measures required to decrease potential worker exposures. 

— Include the following in preplacement 

examinations: 

1. A standardized questionnaire 

that includes detailed medical 

and work histories with emphasis on respiratory or allergic conditions

2. A physical examination that 

centers on the respiratory tract

3. Baseline pulmonary function 

tests (including FEV1 and FVC). 

■ Inform workers who report pre-existing 

asthma or severe allergies on the preplacement examination that it will be difficult to 

monitor their health status and that if they 
18 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

become sensitized to MDI, their asthma 

symptoms are likely to worsen.

■ Conduct periodic examinations to update medical and work histories every 

6 months during the initial 24 months of 

potential exposure and annually thereafter, with repeat pulmonary function tests 

every 1 to 2 years. 

■ Increase the frequency of the periodic 

examinations if indicated by the health 

status of the worker or if there is reason 

to suspect a lapse in control of isocyanate exposures.

■ In case of onset or progression of asthmalike symptoms or excessive declines in 

lung function, arrange for a thorough 

medical evaluation to determine the 

presence of asthma.

— If asthma is present, establish the relationship to the work environment. 

— Ensure that any person who has been 

medically evaluated and determined 

to be sensitized to isocyanates (including MDI) stop all exposure to the 

implicated agent. Several references 

are available to guide the evaluation 

of symptoms in exposed persons 

[Nicholson et al. 2005; FriedmanJiménez et al. 2000].

■ Record and store information in such a 

way as to be usable for both the ongoing respiratory protection program and 

to evaluate the distribution of respiratory 

complaints, patterns of decline in respiratory function, or sentinel events.

■ Although respiratory protection programs 

have a separate function from medical 

monitoring, information obtained through 

a respiratory protection program can be 

incorporated and used as part of an overall medical surveillance program. 

■ Consult published literature for information about how successful medical 

monitoring programs are associated 

with an earlier recognition and improved 

prognosis for workers who develop occupational asthma [Liss et al. 2000; Tarlo 

et al. 2002, 1997a, 1997b, 1995]. 

Surveillance and Disease Reporting

■ To enhance the uniformity of reporting 

work-related asthma, use the reporting guidelines and asthma surveillance 

case definition and case classification 

(see Appendix D). These guidelines and 

case definition, which have been updated 

since the 1996 NIOSH Alert, are recommended for public health surveillance of 

work-related asthma reported by physicians and other health care providers 

[NIOSH 1996; Jajosky et al. 1999]. As of 

2004, six States—California, Massachusetts, Michigan, New Jersey, New York, 

and Washington—are actively engaged 

in work-related asthma surveillance and 

preventive activities; one other State—

Connecticut—has a work-related asthma 

surveillance system in place (see Appendix E for State contact information for 

these States). 

Decontamination and Waste Disposal

■ If you are a manufacturer or distributor, 

establish procedures for decontamination, waste disposal, and transport for 

isocyanate-contaminated materials or 

equipment. Further information about 

waste disposal is available through local, 

State, or Federal EPA offices (www.epa.

gov); the Alliance for the Polyurethanes 

Industry (API) (www.polyurethane.org); 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 1

and MDI and TDI: Safety, Health and the 

Environment [Allport 2003]. 

FUTURE RESEARCH AND

PRODUCTS

NIOSH is continuing research on solutions 

for the spray-on truck bed liner industry 

in collaboration with other government 

agencies, academia, and industry representatives. This research includes the following:

■ Investigation of the particle size distribution of the overspray and the relative 

contributions of gravitational settling and 

ventilation in removing MDI from the atmosphere of the spray enclosure. 

■ Design and evaluation of a negativepressure ventilation system to reduce 

MDI concentrations within the spray 

enclosure and to prevent escape of MDI 

to other areas.

■ Analytical methods research for MDI and 

other isocyanates.

■ Production and dissemination of a 

NIOSH Workplace Solutions document 

detailing ventilation designs and work 

practices for the spray-on truck bed 

liner industry. 

ACKNOWLEDGMENTS 

This Alert was written by Daniel Almaguer, 

M.S.1; M. Kathleen Ernst1; Lisa G. Benaise, 

M.D., M.P.H.2; Robert P. Streicher, Ph.D.1; 

Kenneth R. Mead, M.S., P.E.1; Don J. Lofgren, C.I.H.3; Dave Bonauto, M.D., M.P.H.3; 

Alberto Garcia, M.S.1; Roland Berry Ann1; 

Margaret S. Filios, S.M., R.N.1; and Edward 

Lee Petsonk, M.D.1

Stanley A. Shulman, Ph.D.,1 provided statistical support and G. Edward Burroughs, 

Ph.D., C.I.H., C.S.P.,1 provided guidance 

and review. 

Susan Afanuh, Anne C. Hamilton, and Vanessa Becks provided editorial and production 

services.

Please direct comments, questions, or requests for additional information to the following: 

Dr. Mary Lynn Woebkenberg

Director, Division of Applied Research

 and Technology

National Institute for Occupational Safety

 and Health

4676 Columbia Parkway

Cincinnati, OH 45226–1998

Telephone: 513–533–8462; or call

1–800–35–NIOSH (1–800–356–4674) 

We greatly appreciate your assistance in 

protecting the lives of U.S. workers.

John Howard, M.D.

Director, National Institute for

 Occupational Safety and Health

Centers for Disease Control

 and Prevention

1NIOSH; 2Centers for Disease Control and Prevention; 3Washington State Department of Labor and Industries
REFERENCES 

ACGIH [2004]. Industrial ventilation: a manual of recommended practice. 25th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, Committee 

on Industrial Ventilation. 

Allport DC, Gilbert DS, Outterside SM [2003]. 

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 APPENDIX A 

Figure 1. MDI Monomer 

This appendix includes (1) a definition of 

isocyanates and MDI terms used in the text, 

(2) a list of commonly used synonyms for 

MDI monomer, (3) a table of Chemical Abstract Service (CAS) numbers associated 

with MDI, their CAS name and common 

names or descriptions, and (4) a table of 

several manufacturers’ MDI-based products 

used in the truck bed liner industry and their 

associated CAS numbers. 

ISOCYANATE DEFINITIONS AND 

CHEMICAL STRUCTURE

An isocyanate is any compound that contains the -NCO functional group. A functional group is any group of atoms that 

represents a potential reaction site in an 

organic compound. An isocyanate thus has 

a nitrogen (N), carbon (C), and oxygen (O) 

bonded together in such a way as to create a reactive site within the molecule. In 

this document, the term diisocyanate refers to a chemical compound that contains 

two isocyanate groups (NCO) per molecule. 

When specifically referring to the diisocyanate methylenebis(phenyl isocyanate), the 

term MDI monomer will be used. The MDI 

monomer is depicted in Figure 1. The term 

MDI refers to a mixture containing any combination of MDI monomer, MDI prepolymer, 

or polymeric MDI.

The spray-on truck bed liner industry uses 

MDI-based products as one component of 

a two component spray-on process. Component A typically contains a mixture of MDI 

monomer(s) and modified MDI. All have reactive isocyanate groups present and should 

be considered possible health hazards. 
26 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

Methylenebis(phenyl isocyanate) Synonyms

MDI 

1,1-Methylenebis(4-isocyanatobenzene) 

4,4’-Diisocyanatodiphenylmethane 

4,4’-Diphenylmethane diisocyanate 

4,4’-Methylenebis(phenyl isocyanate) 

4,4’-Methylenediphenyl diisocyanate 

Bis(1,4-isocyanatophenyl)methane 

Bis(4-isocyanatophenyl)methane 

Diphenylmethane 4,4’-diisocyanate 

Diphenylmethane diisocyanate 

Methylenebis(4-isocyanatobenzene) 

Methylenebis(4-phenylene isocyanate) 

Methylenebis(phenyl isocyanate) 

Methylene-di-p-phenylene isocyanate 

Methylene di(phenylene isocyanate) 

Methylene bisphenyl isocyanate (Chemical name used in OSHA documents.) 

Sources: Lewis [1993], NIOSH [1995], Sax and Lewis [1987]. 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 27

Table 1. CAS numbers associated with MDI*

CAS number CAS preferred name

Description/

common names

101–68–8 benzene, 1,1’-methylenebis[4-isocyanato- 4,4’-MDI isomer, pure MDI

5873–54–1 benzene, 1-isocyanato-2-[(4-isocyanatophenyl) 

methyl]-

2,4’-MDI isomer

2536–05–2 benzene, 1,1’-methylenebis[2-isocyanato- 2,2’-MDI isomer

26447–40–5 benzene, 1,1’-methylenebis[isocyanato- MDI (generic), mixture of isomers

9016–87–9 isocyanic acid,

polymethylenepolyphenylene ester

PMDI, polymeric MDI (generic), 

mixture of chemical homologues 

made from the phosgenation of 

the reaction product of aniline 

and formaldehyde

25686–28–6 benzene, 1,1’-methylenebis[4-isocyanato-, 

homopolymer

Main components of polymeric 

MDI, mixture of chemical homologues derived from the 4,4’-

MDI isomer

17589–24–1 1,3-diazetidine-2,4-dione, 1,3-bis[4-

[(4-isocyanatophenyl) methyl]phenyl]-

4,4’-MDI dimer, self-reaction 

product

31107–36–5 1,3-diazetidin-2-one, 1,3-bis[4-[(4-

isocyanatophenyl) methyl]phenyl]-4-[[4-

[(4-isocyanatophenyl)methyl]phenyl]imino]-

Uretonimine of 4,4’-MDI, a 

modified MDI (variant) made 

from self-reaction of 4,4’-MDI at 

high temperatures

39310–05–9 benzene, 1,1’-methylenebis[isocyanato-, 

homopolymer

Generic polymeric MDI, mixture 

of chemical homologues derived 

from the mixture of MDI isomers

Source: Allport et al. [2003].

*

This list is not all inclusive.
Table 2. CAS numbers associated with specific MDI products†

Company CAS number Description

The Dow Chemical

 Company

26447–40–5 5 MDI products support the TBL business. 

All but one contains MDI prepolymers, which 

generally do call out the MDI prepolymer CAS 

number on the MSDS. 

Bayer MaterialScience 39420–98–9 Bayer systems that are sold into the TBL industry are identified as Baytec SPR 085A and Baytec SPR 092A. Component A of each of these 

systems contains the MDI-based isocyanate. 

Rhino Lining 26447–40–5

101–68–8 

9016–87–9

The first two CAS numbers are for commercial 

Tuff Stuff A Side. The last CAS number is for 

PMDI (Durabond A Side)

Line-X Corporation 26447–40–5

Huntsman Polyurethanes

101–68–8

101–68–8

26447–40–5 

39420–98–9

101–68–8

(not disclosed)

101–68–8

(not disclosed)

101–68–8

(not disclosed)

 MDI product name/Chemical name(s) 

RUBINATE® 8001/

4,4’-Diphenylmethane Diisocyanate 

RUBINATE® 1209/

4,4’-Diphenylmethane Diisocyanate 

RUBINATE® 9465/

Generic Diphenylmethane Diisocyanate

Modified MDI 

RUBINATE® 9495/

4,4’-Diphenylmethane Diisocyanate

Modified MDI

RUBINATE® 9009/

4,4’-Diphenylmethane Diisocyanate

Modified MDI 

SUPRASEC® 9537/

4,4’-Diphenylmethane Diisocyanate

Modified MDI

Source: API

†

This list is not all inclusive.
APPENDIX B

SPRAY ENCLOSURE/VENTILATION 

DESIGN CONSIDERATIONS 

This Appendix contains information about 

spray enclosure and ventilation design, including how to determine the number of air 

changes per hour and calculate the minimum required purge time. 

When substitution is not feasible, engineering controls should be the primary method 

for reducing airborne isocyanates in the 

workplace. Spray enclosures should incorporate exhaust ventilation systems designed 

to contain, capture and remove vapors and 

particulates. It is generally advisable to 

minimize the size and volume of the spray 

area while seeking to increase the exhaust 

capacity from the spray area. General design concepts and operating considerations 

for the ventilation control of occupational 

exposures may be found in the most recent 

edition of Industrial Ventilation: A Manual 

of Recommended Practice, published by 

the American Conference of Governmental Industrial Hygienists (ACGIH) [ACGIH 

2004b]. 

The design and operation of a ventilated 

spray enclosure for MDI-based spray-on 

bed liners should include the following four 

parameters with the aim of containing and 

minimizing exposure to MDI and maintaining 

exposure to MDI monomer below the NIOSH 

10-minute ceiling limit and OSHA 15-minute 

ceiling limit of 0.2 mg/m3: 

1. The spray enclosure should be designed as a negative pressure enclosure to prevent leakage of airborne 

MDI into other work areas within the 

shop. Three different design configurations have been identified to lower MDI 

concentrations within the spray enclosure and prevent escape to adjacent 

work areas:

■ A spray booth similar to that used 

in the automotive paint spray industry; or

■ A spray enclosure (smallest floor 

area and room volume compatible with the operation) that incorporates local exhaust ventilation 

hood(s) to capture and remove 

MDI near the point(s) of generation; or 

■ A spray enclosure (smallest floor 

area and room volume compatible with the operation) that uses 

a general ventilation system to 

dilute airborne contaminants. 

The ventilation system’s make-up 

air supply and exhaust locations 

should be strategically placed to 

generate a directed air flow that 

pushes airborne contaminant toward the exhaust points to maximize ventilation efficiency and 

contaminant control. 

2. If MDI were removed solely by dilution 

ventilation using an efficient (well-mixed) 

system design, the recommended three 
30 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

enclosure (see Respiratory Protection in 

Recommendations). 

Purge Time

■ To calculate the time required to exhaust 

an air volume equal to a single room air 

change, you must know the exhaust capacity of the fan (as installed) as well as 

the dimensions of the spray area. 

T= (L × W × H)

Q

where:

T = time for one air change

 (minutes)

L = length of spray enclosure (feet)

W = width of spray enclosure (feet)

H = height of spray enclosure (feet)

Q = fan capacity in cubic feet per

 minute (cfm) 

■ A minimum purge time of three air 

changes (3×T) is recommended for 

spray enclosures that incorporate very 

good ventilation efficiency (that is, mixing factor close to 1.0), such as those 

discussed in item 1 above. Less efficient 

designs will need to multiply the calculated time requirement by a mixing factor between 2 and 10, depending upon 

the prevalence of dead air spots within 

the spray area [ACGIH 2004]. During the 

recommended purge time, workers entering the spray enclosure should continue using respiratory protection.

air changes would be sufficient to 

remove 95% of the airborne MDI after spraying has ceased. However, 

NIOSH field experience has shown 

that gravitational settling contributes 

significantly to the removal of the MDI 

aerosol. When these two removal 

mechanisms act together, the time 

required to achieve three air changes 

was more than sufficient to reduce the 

MDI concentrations to less than 50% 

of the NIOSH ceiling limit in every field 

situation evaluated by NIOSH. During 

the purge time any worker entering the 

spray enclosure should continue to use 

the necessary respiratory protection 

(see Respiratory Protection section).

Ventilation System Capabilities

■ Obtain a site-specific exposure assessment that includes sampling data at desired intervals following the spraying operation. These data are the best way to 

determine the purge time (time required 

to reduce MDI concentrations consistently below the NIOSH REL) required for your 

ventilation system.

■ In the absence of exposure assessment 

data, determine the time required for the 

ventilation system to exhaust an air volume equal to a single air change.

■ Calculate the required purge time, allowing sufficient time for at least three complete air exchanges—or even longer for 

systems with poor air mixing.

■ During the purge time, use respiratory protection when entering the spray 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 31

APPENDIX C

This appendix contains additional information about full-facepiece, supplied-air respirators and a respiratory protection program. 

SUPPLIED-AIR RESPIRATORS

Many issues pertaining to this industry led 

to the selection of the full-facepiece, supplied-air respirator as the most appropriate respirator during the spray-on process. 

These reasons include the following: 

■ MDI is a potent sensitizer and a NIOSHapproved supplied-air respirator provides 

a higher level of protection, thus lowering 

the potential for sensitization.

■ A supplied-air respirator provides the 

high level of protection needed in a work 

environment in which concentations of 

MDI aerosol are highly variable with unpredictable spikes to concentrations well 

above the NIOSH REL.

■ A supplied-air respirator decreases the 

possibility of momentary breakthrough in 

a work environment in which an air-purifying filter cartridge would likely become 

clogged, leading to higher breathing resistance and leakage around the side of 

the mask.

■ Full-facepiece, supplied-air respirators 

provide the eye and dermal protection 

necessary from the aerosolized spray-on 

product.

■ An air-purifying respirator requires frequent cartridge changes due to the concentrations documented. 

ELEMENTS OF A RESPIRATORY 

PROTECTION PROGRAM

A complete respiratory protection program 

as required by 29 CFR 1910.134 (c) (1) (i) 

through 1910.134 (c) (1) (ix) shall include 

the following: 

■ Procedures for selecting respirators for 

use in the workplace

■ Medical evaluations of employees required to use respirators

■ Fit-testing procedures for tight-fitting respirators

■ Procedures for proper use of respirators 

in routine and reasonably foreseeable 

emergency situations

■ Procedures and schedules for cleaning, 

disinfecting, storing, inspecting, repairing, discarding, and otherwise maintaining respirators

■ Procedures to ensure adequate air quality, quantity, and flow of breathing air for 

atmosphere-supplying respirators

■ Training of employees in the respiratory 

hazards to which they are potentially 

exposed during routine and emergency 

situations
3 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

■ Training of employees in the proper use 

of respirators, including putting on and 

removing them, any limitations on their 

use, and their maintenance

■ Procedures for regularly evaluating the 

effectiveness of the program 

Appropriate management is a critical part of 

an effective respiratory protection program. 

Therefore, the program should be evaluated 

regularly as required by 1910.134 (c) (1) 

and administered by a qualified program 

administrator as required by 1910.134 (c) 

(3). Workers using supplied-air respirators 

must follow the manufacturer’s instructions 

on how to maintain and verify the specified 

minimum air pressure for the respirator. 
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 33

APPENDIX D

Surveillance Guidelines for State Health Departments 

Work-Related Asthma 

1 second (FEV1) or peak expiratory flow rate. 

Airflow changes can occur spontaneously, 

with treatment, with a precipitating exposure, or with diagnostic maneuvers such as 

nonspecific inhalation challenge. 

Patterns of association can vary and include 

the following: 

■ Symptoms of asthma that develop or 

worsen after a worker starts a new job or 

after new materials are introduced on a 

job (a substantial period can elapse between initial exposure and development 

of symptoms)

■ Symptoms that develop within minutes of 

specific activities or exposures at work

■ Delayed symptoms that occur several 

hours after exposure (for example, during the evenings of workdays)

■ Symptoms that occur less frequently or 

not at all on days away from work and on 

vacations

■ Symptoms that occur more frequently 

when the affected worker returns to work

■ Symptoms that are temporally associated with workplace exposure to an agent 

with irritant properties

Work-related changes in medication requirements can accompany these symptom patterns.

 REPORTING GUIDELINES

State health departments should encourage 

health-care professionals to report back all 

the diagnosed or suspected cases of asthma 

that are caused or exacerbated by workplace 

exposures or conditions. Reported cases 

should include asthma caused by sensitizers 

or irritants and should include cases of reactive airways dysfunction syndrome. 

SURVEILLANCE CASE DEFINITION

The surveillance case definition requires

1. a health care professional’s diagnosis 

consistent with asthma and 

2. an association between symptoms of 

asthma and work. 

Asthma is a chronic condition characterized 

by inflammation of the tracheobronchial tree 

associated with increased airways responsiveness to a variety of stimuli. Symptoms 

of asthma include episodic wheezing, chest 

tightness, cough, and dyspnea, or recurrent 

attacks of bronchitis with cough and sputum 

production. The primary physiological manifestation of airways hyperresponsiveness is 

variable or reversible airflow obstruction. It 

is commonly demonstrated by significant 

changes in the forced expiratory volume in 
3 MDI Exposure During Spray-on Truck Bed Liner and Related Applications 

APPENDIX E

Contact Information for Selected States 

The following States have surveillance systems for work-related asthma: 

California 

California Department of Health Services

Occupational Health Branch

850 Marina Bay Parkway

Building P, 3rd Floor

Richmond, CA 94804–6404

510–620–5757

www.dhs.ca.gov/ohb/Default.htm

CAL/OSHA Consultation Service

Department of Industrial Relations

2424 Arden Way, Suite 485

Sacramento, California 95825

916–263–5765 

www.dir.ca.gov/DOSH/consultation.html

Connecticut

State of Connecticut Department of

 Public Health

410 Capitol Avenue, Mail Stop: 11 OSP

P.O. Box 340308

Hartford, CT 06134–0308

860–509–7744

www.dph.state.ct.us/BRS/EOHA/HPEEOH.html

Connecticut Department of Labor

Division of Occupational Safety and Health

38 Wolcott Hill Road

Wethersfield, CT 06109

860–566–4550

www.ctdol.state.ct.us/osha/osha.htm

Massachusetts

Massachusetts Department of

 Public Health

Occupational Health Surveillance Program

250 Washington Street, 6th Floor

Boston, MA 02108

617–624–5632

www.mass.gov/dph/bhsre/ohsp/ohsp.htm

MA Division of Occupational Safety

On-site Consultation Program

Department of Labor and

 Workforce Development

1001 Watertown Street

West Newton, MA 02465

617–969–7177

www.mass.gov/dos/consult/index.htm

Michigan

Michigan Department of Labor and

 Economic Growth

Michigan Occupational Safety and Health

 Administration (MIOSHA)

Consultation, Education, and

 Training Division

7150 Harris Drive

P.O. Box 30659

Lansing, MI 48909–8149

517–322–1809 

www.michigan.gov/cis/0,1607,7-154-

11407---,00.html
MDI Exposure During Spray-on Truck Bed Liner and Related Applications 35

Michigan State University

Department of Medicine

Occupational and Environmental Medicine

117 West Fee Hall

East Lansing, MI 48824–1315

517–432–1008

www.oem.msu.edu

New Jersey

New Jersey Department of Health

 and Senior Services

Occupational Health Surveillance Program

P.O. 360, Room 701

Trenton, NJ 08625–0360

609–984–1863 

www.nj.gov/health/eoh/survweb

NJ Department of Health and Senior Services

Public Employees Occupational Safety

 and Health Consultation Project

P.O. Box 360

Trenton, NJ 08625–0386

609–984–1863

www.state.nj.us/health/eoh/peoshweb/

peoshcon.htm

New Jersey Department of Labor

 and Workforce Development

Division of Public Safety and Occupational

 Safety and Health

P.O. Box 953, Trenton, NJ 08625

609–984–0785

www.state.nj.us/labor/lsse/lsonsite.html

New York

State of New York Department

 of Health

Center for Environmental Health

Bureau of Occupational Health

Flanigan Square

547 River Street, Room 230

Troy, New York 12180–2216

518–402–7900 

www.health.state.ny.us/nysdoh/boh/

homeoccu.htm

New York State Department

 of Labor

Division of Safety and Health

Onsite Consultation Program

State Office Campus, Bldg. 12, RM 168

Albany, New York 12240

518–457–2238

www.labor.state.ny.us/

Washington 

Washington State Department of Labor

 and Industries

Safety and Health Assessment and

 Research for Prevention (SHARP) Program

P.O. Box 44330

Olympia, WA 98504–4330

888–667–4277

www.lni.wa.gov/Safety/Research/default.asp