Air Monitoring Applications - Paints & Coatings

Paints & Coatings - Binding Agent

A binding agent or “vehicle” is one of the three components of paints. It bonds the paint pigment, remains on the coated surface when dry, and also gives paints its protective properties. Binders include synthetic or natural resins, including: acrylics, polyurethanes (contain isocyanates), polyesters, melamine resins, epoxy, or oils.

Urethane Binders: Isocyanates

Isocyanates are toxic compounds used in the formation of urethane compounds. The isocyanate group reacts with hydroxyl to form a urethane structure. Isocyanates are highly reactive and exposure can result in workplace asthma and ‘hypersensitivity pneumonitis’ through inhalation or skin contact. Other symptoms include tightness in the chest, difficulty with breathing, and sensitivity to skin and mucous membranes. Workers may be exposed to isocyanates during the manufacture of urethane products; also in foam-blowing applications including insulation, foam-in-place packaging, surface coatings, furniture manufacture, mattresses, padding, shoes, laminated fabrics, etc.

Isocyanates are commonly used in the formation of urethane polymers, urethane paint, spandex fibers, thermoplastic elastomers. They are the compounds that make up all polyurethane products; there is no substitute.

Current sampling methods for isocyanates pose an industry challenge. Sampling devices are suitable only for STEL sampling, and may not be indicative of true isocyanate exposure. Often, the worker must be removed from their work area first to be outfitted with the sampler, and then again to retrieve the sampler, resulting in lost time and productivity. Additionally, existing methods require immediate field desorption after sampling in order to avoid the risk of unreliable results. Adding to the challenge is the inconvenience of shipping samplers and reagents to and from the sampling location (for sampling and analysis), resulting in some loss of samples due to sampler storage instability.

Our new ASSET™ EZ4-NCO dry sampler for isocyanates overcomes these challenges by offering the ultimate sensitivity, stability, and confidence, with reliable results.

Exposure Limits
Agency Exposure Limit
2,4-TDI and 2,6-TDI
OSHA (PEL) for General Industry: 0.02 ppm; 0.14 mg/m³ ppm TWA
for Construction Industry: 0.02 ppm; 0.14 mg/m³ ppm TWA
for Maritime: 0.02 ppm; 0.2 mg/m³ ppm TWA
ACGIH (TLV) 0.005 ppm, 0.036 mg/m³ TWA; 0.02 ppm, 0.14 mg/m³ STEL; SEN; Appendix A4 - Not Classifiable as a Human Carcinogen
NIOSH (IDHL) 2.5 ppm
MDI
OSHA (PEL) for General Industry: 0.02 ppm; 0.2 mg/m³ ppm TWA
for Construction Industry: 0.02 ppm; 0.2 mg/m³ ppm TWA
for Maritime: 200 ppm; 590 mg/m³ ppm TWA
ACGIH (TLV) 0.005 ppm, 0.051 mg/m³ TWA
NIOSH (REL) 0.005 ppm TWA; 0.020 ppm Ceiling (10 min)
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit; IDHL=Immediately Dangerous to Life and Health concentration)

References
OSHA Standard - Isocyanates
NIOSH Safety and Health Topic - Isocyanates
US EPA – Isocyanates Profile; Toxic Substance Control Act (TSCA) Chemical Action Plan 
Health and Safety Executive (HSE, UK) - Isocyanates
ISOPA Emissions Toolbox

Air Sampling Media by Regulatory Method
Method Contaminants of Interest Sampling Media
OSHA
OSHA 42 Diisocyanates Filter – Glass Fiber Filter Coated w/1-2PP (20811/20812-U)
New! Dry Sampler – ASSET EZ4-NCO Dry Sampler (5027-U/5028-U)
OSHA 47 Methylene Bisphenyl Isocyanate (MDI) Filter – Glass Fiber Filter Coated w/1-2PP (20811/20812-U)
New! Dry Sampler – ASSET EZ4-NCO Dry Sampler (5027-U/5028-U)
NIOSH
NIOSH 5521 Isocyanates Impinger (20270-U)
New! Dry Sampler – ASSET EZ4-NCO Dry Sampler (5027-U/5028-U)
NIOSH 5522 Isocyanates Impinger (20270-U)
New! Dry Sampler – ASSET EZ4-NCO Dry Sampler (5027-U/5028-U)
EPA
EPA 207 Isocyanates in Stationary Source Emissions Impinger (20270-U)
New! Dry Sampler – ASSET EZ4-NCO Dry Sampler (5027-U/5028-U)

Applications
Analysis of 1-(2-pyridyl)-piperazine (2PP) Derivatives of Di-isocyanates Using Discovery® HS F5 (pdf)
Analysis of 1-(2-pyridyl)-piperazine (2PP) Derivatives of Di-isocyanates Using Discovery® Cyano (pdf)
Analysis of 1-(2-pyridyl)-piperazine (2PP) Derivatives of Di-isocyanates Using Ascentis™ RP-Amide (pdf)
Isocyanates by OSHA 42, 47, ASTM® D5836
Monitor Airborne Diisocyanates Using ORBO™-80 Coated Filters (pdf)

Related Products
LC-MS/MS: Ascentis Express C18, 5 cm x 2.1 mm, 2.7 μm particles (53822-U)
ORBO 80 Coated Filter, with cassettes (20812-U), without cassettes (20811)
SUPELCOSIL LC-CN HPLC Column, 5 µm particle size, 25 cm × 4.6 mm (58231)
Isocyanate Standards and Derivatives