Prevention Guidance for Isocyanate-Induced Asthma Using Occupational Surveillance Data

Figures & data

TABLE I Distribution of Isocyanate-Induced Asthma Cases Across NAICS Code Sector (2-digit) and National Industry (6-digit)

	# Isocyanate-induced
NAICS Code	asthma cases
23 Construction
238320 Painting and wall covering contractors	2
238310 Drywall and insulation contractors	1
31–33 Manufacturing
325510 Paint and coating manufacturing	2
336411 Aircraft manufacturing	2
313230 Nonwoven fabric mills	1
326199 All other plastic product manufacturing	1
327991 Cut stone and stone product manufacturing	1
332321 Metal window and door manufacturing	1
332999 All other misc. fabricated metal product mfg.	1
336214 Travel trailer and camper manufacturing	1
336612 Boat building	1
339950 Sign manufacturing	1
42 Wholesale Trade
423990 Other misc. durable goods merchant wholesalers	1
54 Professional, scientific, and technical services
541330 Engineering services	1
81 Other services
811121 Automotive body, paint, and interior repair and maintenance	8
92 Public administration
922160 Fire protection	1
924110 Admin. of air and water resources and solid waste mgmt.	1
Total # cases	27
Note: NAICS, North American Industry Classification System, 2007.

TABLE II Distribution of Isocyanate-Induced Asthma Cases Across Occupations

Standard Occupational Classification (SOC) code	# Isocyanate-induced asthma cases
11 Management Occupations
119199 Managers, All Other	1
33 Protective Service Occupations
332011 Firefighters	1
43 Office and Administrative Support Occupations	1
439061 Office Clerks, General
47 Construction and Extraction Operations
472061 Construction Craft Laborer	1
472141 Painters, Construction, and Maintenance	3
49 Installation, Maintenance, and Repair Occupations
491011 First-Line Supervisors of Mechanics, Installers, and Repairers	1
493021 Automotive Body and Related Repairers	1
51 Production Occupations
512099 Assemblers and Fabricators, All Other	5
514000 Metal Workers and Plastic Workers	2
519112 Painters, Transportation Equipment	1
519121 Coating, Paint, and Spraying Machine Setters, Operators, and Tenders	1
519122 Painters, Transportation Equipment	5
519199 Production Workers, All Other
53 Transportation and Material Moving Occupations	3
537051 Industrial Truck and Tractor Operators	1
Total # cases	27
Note: SOC, Standard Occupational Classification System, 2010

TABLE III Summary of the Processes and Trends Associated with Isocyanate-Induced Asthma

	# Isocyanate-induced	# Cases involving	# Cases indirect
Process	asthma cases	large objects	exposure
Painting (total cases)	15	7	2
Automotive	8	2	1
Industrial coating	4	4	1
Signs	2	1	–
Unknown	1	–	–
Foam (total cases)	5	–	3
Manufacturing	2	–	2
Packaging (shipment of goods)	2	–	–
Building insulation	1	–	1
Adhesives in aircraft mfg.	2	2	–
Truck bed liner application	2	–	–
Resin and molds in production mfg.	2	–	1
Sealant	1	–	–
Total	27	9	6
Note: All cases of indirect exposure to isocyanates were classified as New Onset Asthma (NOA).

TABLE IV Characterization of Isocyanate-Induced Asthma Cases Identified Through a Surveillance System

ID	Job Title	NAICS	Process (Isocyanate)	Respiratory Protection	Asthma
1	Missile Craftsman	541330	Paint, industrial: Acute exposure from isocyanate spill in mix room. Otherwise assemble, disassemble and repair missiles.	Respirator used, type not specified.	NOA
2	Painter, industrial equipment	336612	Paint, industrial: Auto painting, heavy industrial equipment.	Had used APR. Began using a SAR at symptom onset.	NOA
3	Painter, concrete coating	238320	Paint, industrial coating (MDI): Line inside of city sewer pipe with coating; Assistant to main sprayer.	Half mask, SAR used inconsistently -indirect exposure.	NOA
4	Painter, industrial journeyman	924110	Paint, industrial coating: Applied spray coatings in a construction setting.	‘Full’ PPE required when spraying product; injured worker felt exposure came from handling containers in storage area, when no PPE used.	NOA
5	Painter, industrial signs	238320	Paint, signs: Spray coat aluminum signs in spray booth with four to five other workers; spray large signs.	Dust mask	NOA
6	Painter and sign fabricator	339950	Paint, signs: Unknown process. Records state respirator was often removed to facilitate breathing	APR	WAA
7	Painter	325510	Paint (polyurethane): Process not specified, various coating applications inside booth.	Half-face occasionally worn.	NOA
8	Forklift driver	313230	Foam manufacture (TDI): Transport foam buns, using forklift, between cure and ship areas of manufacturing plant. Did not work directly with TDI.	None used - indirect exposure.	NOA
9	Equipment technician	325510	Foam manufacture (MDI, TDI and HDI): Worker cleaned spray guns and performed other duties. Foam mfg. occurred inside spray booths.	Occasionally wears half face APR and PAPR - indirect exposure.	NOA
10	Assembler	326199	Foam packing (MDI): Assemble small machines; spray packing foam around them for protection during shipment. Foam is applied inside a booth, but boxes cure on open floor.	Unknown	Unk
11	Aerospace assembler	332999	Foam packing (TDI): Build and solder mechanical boxes; surround boxes with foam spray for protection during shipping.	Unknown	WAA
12	Assistant, residential foam insulator	238310	Foam insulation (MDI): Assist application in small residential attic, no ventilation.	Dust mask at first SOB episode, APR at second episode. Indirect exposure.	RADS
13	Unknown	336411	Adhesive: Spray aircraft doors.	Unknown	NOA
14	Interiors mechanic	336411	Adhesive: Spray aircraft panels.	Unknown	NOA
15	Mgr. and Sprayer, truck bed linings	811121	Truck bed liner (MDI): Mix and spray truck bed linings. Worker suspected that exposure while vehicle unmasking contributed to his exposure.	APRs and PAPR for 2.5 years, then SAR for the last 9 months.	NOA
16	Sprayer, truck bed linings	811121	Truck bed liner (MDI): Mix and spray truck bed linings.	Full face SAR. Faulty air supply to respirator.	NOA
17	Sprayer; mold maker	327991	Polyurethane resin and mold (MDI): Synthetic rock manufacturing. Process uses molds to form the rocks.	Unknown	WAA
18	Tire press operator	423990	Polyurethane resin and mold (MDI): Worked in tire mounting and de-molding area. Urethane tire production involved injection of MDI product into hot molds.	None used - indirect exposure.	NOA
19	Production Worker	332321	Sealant (MDI): Apply sealant to glass at insulated glass manufacturer.	Unknown	RADS
20	Painter and Stainer	336214	Paint, automotive: Paint campers and trailers.	Unknown	NOA
21	Firefighter, fire truck fabricator, painter	922160	Paint, automotive (HDI, IPDI): Paint fire trucks and truck parts in unventilated wash bay.	Dust mask	NOA
22	Manager, automotive office	811121	Paint, automotive: Painting occurs on shop floor, outside of booth.	None used - indirect exposure.	NOA
23	Painter, automotive	811121	Paint, automotive: Paint autos.	Inconsistent use of APR and SAR	WAA
24	Painter, automotive	811121	Paint, automotive (HDI, IPDI): Paint autos.	SAR used	NOA
25	Painter and Mgr., automotive	811121	Paint, automotive: Paint autos.	PPE not used 10 years ago.	NOA
26	Painter, automotive	811121	Paint, automotive (HDI, IPDI): Paint autos and prep work.	Half-face APR at time of attack. Wore PAPR after attack.	WAA
27	Painter, automotive	811121	Paint, automotive (HDI, IPDI): Paint autos.	Full face SAR used in paint booth.	NOA
Notes: NAICS, North American Industry Classification System; when specifically known, the isocyanates are given for the process. TDI, toluene diisocyanate; MDI, methylene diphenyl diisocyanate; HDI, hexamethylene diisocyanate, IPDI, isophorone diisocyanate. Information in the claim records was not sufficient to distinguish between monomeric or oligomeric isocyanate forms. APR, air purifying respirator; PAPR, powered-air purifying respirator; SAR, supplied air respirator; PPE, personal protective equipment; WAA, work-aggravated asthma; NOA, new-onset asthma; RADS, reactive airways dysfunction syndrome (a type of NOA)

TABLE V SENSOR Asthma Classification for Isocyanate-Induced Asthma Cases Compared to “All Other” Asthma Cases

	Asthma cases from isocyanates 1999 – 2010	Asthma cases from “all other” agents 2001 – 2010
Total # Cases	27	1438
-Males (%)	24 (89)	590 (38)
# Classified with Diagnosis	26	571
New Onset Asthma (%)	21 (81)	301 (52)
-RADS (%)	2 (8)	62 (11)
Work-Aggravated Asthma (%)	5 (19)	270 (47)
Notes: SENSOR, Sentinel Event Notification System for Occupational Risk; Two cases of isocyanate-induced asthma were identified between 1999 and 2001, before formal institution of the surveillance system; RADS, Reactive Airways Dysfunction Syndrome

TABLE VI Workers’ Compensation Cost and Time Loss for Isocyanate-Induced Asthma Cases Compared to All Other Asthma Cases

	Isocyanate-induced	All other asthma cases
Cost	asthma cases 1999–2010	2001–2010
Total # All Cases	n = 22	n = 839
Total cost ($)	1,723,867	10,765,746
Median ($)	22,885	520
Medical-only ($)	n = 8	n = 584
Median	1,173	398	p < 0.08
Q1–Q3	1,099–1,247	154–881
Max	88,229	75,894
Compensable ($)	n = 14	n = 255
Median	48,112	3,366	p < 0.0006
Q1 – Q3	17,632–82,213	719–19,546
Max	593,032	554,944
Time loss (days)	n = 14	n = 255
Median	367	39	p < 0.0005
Q1 – Q3	56–954	0–80
Max	2,375	3,788
Notes: Cost data available only for medical claims covered by Washington's state insurance system; Compensable claim costs include payment for time lost from work, medical costs, disability awards, and pension costs; all reported p-values are Kruskal-Wallis rank test; Two cases of isocyanate-induced asthma were identified between 1999 and 2001, before formal institution of the surveillance system