CDC logoSafer Healthier People CDC HomeCDC SearchCDC Health Topics A-Z
NIOSH - National Institute for Occupational Safety and Health

Skip navigation links Search NIOSH  |  NIOSH Home  |  NIOSH Topics  |  Site Index  |  Databases and Information Resources  |  NIOSH Products  |  Contact Us
NIOSH Home > Safety and Health Topics >Skin Exposures and Effects >Occupational & Environmental Exposures of Skin to Chemicals- 2005> Abstracts

• Main Page
• General
Information
• Co-sponsors
• List of Planners
• Poster Awards
• Program
• Concise Schedule
• Workshops
• Short Courses
•

Talks, Workshops and Posters by Theme

• Vendor Exhibits and Seminars
• Author Index

Abstract for Poster 12

 

 

Development of a tape-strip method to quantify dermal exposure to hexamethylene diisocyanate

K.W. Fent*, K. Jayaraj, A. Gold, L.M. Ball, L.A. Nylander-Fench
University of North Carolina, Chapel Hill, United States

Significant skin contact with 1,6-hexamethylene diisocyanate (HDI) occurs during the application and manufacture of surface coatings, foams, resins, and plastics. Respiratory sensitization and occupational asthma have long been associated with airborne isocyanate exposure, but a similar association with dermal exposure to isocyanates has largely been left unexplored, mainly due to nonexistent quantitative methods for assessing dermal exposure. The objective of this study was to develop a non-invasive technique using tape-strips to sample layers of the epidermis for determination of HDI concentrations in the skin. 

Quantification of HDI on tape-strip samples following derivatization reaction with 1-(2-methoxyphenyl)-piperazine was performed using liquid chromatography and mass spectrometry with electrospray ionization in positive ion mode. The derivative was synthesized independently and shown to be pure by proton NMR and melting point analysis. The ion at m/z 553.4, corresponding to the protonated molecular ion for the derivative was used for quantitation. This method was tested by applying HDI-containing products to tape-strip samples, performing derivatization and quantitative analysis, and determining the recovery of HDI from the tape. The applicability of this method in the occupational setting was investigated by performing dermal tape-strip sampling on auto-body shop workers exposed to HDI-containing paint. Three to five consecutive tape-strip samples were collected for each sampling site on the skin of the exposed workers directly following painting processes in order to determine the extent of dermal absorption of HDI.

The analytical limit of detection for this method is 0.002 pmol/μL, corresponding to 10 pmol of HDI per tape-strip, while the limit of quantification is 0.005 pmol/μL, corresponding to 25.5 pmol of HDI per tape-strip sample. The recovery of HDI from the tape-strip samples ranged from 92.0 to 105.3% (Mean 99.3%). The derivative of HDI was shown to be stable over time with an estimated degradation of < 0.5% per day when stored at -40° C. The quantifiable amounts of HDI from the skin of exposed workers ranged from 26.7 pmol to 1040 pmol of HDI per 10 cm2 tape-strip. The amount of HDI was observed to decrease with each consecutive tape-strip in all monitored exposed sites indicating penetration of HDI into the skin. 

This method is highly sensitive, specific, and suitable for quantification of dermal exposure to HDI in occupational settings. This method will be used to measure dermal exposure to HDI in conjunction with inhalation and biological monitoring during spray-painting processes in order to investigate the contribution of dermal exposure to total body burden.

Content last modified: 15 May 2005

Return