Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

An FTIR investigation of isocyanate skin absorption using in vitro guinea pig skin.

Authors
Bello-D; Smith-TJ; Woskie-SR; Streicher-RP; Boeniger-MF; Redlich-CA; Liu-Y
Source
J Environ Monit 2006 May; 8(5):523-529
NIOSHTIC No.
20030221
Abstract
Isocyanates may cause contact dermatitis, sensitization and asthma. Dermal exposure to aliphatic and aromatic isocyanates can occur in various exposure settings. The fate of isocyanates on skin is an important unanswered question. Do they react and bind to the outer layer of skin or do they penetrate through the epidermis as unreacted compounds? Knowing the kinetics of these processes is important in developing dermal exposure sampling or decontamination strategies, as well as understanding potential health implications such exposure may have. In this paper the residence time of model isocyanates on hairless guinea pig skin was investigated in vitro using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometry. Model isocyanates tested were octyl isocyanate, polymeric hexamethylene diisocyanate isocyanurate (pHDI), polymeric isophorone diisocyanate isocyanurate (pIPDI) and methylenediphenyl diisocyanate (MDI). Isocyanates in ethyl acetate (30 microL) were spiked directly on the skin to give 0.2-1.8 micromol NCO cm(-2) (NCO = -N[double bond, length as m-dash]C[double bond, length as m-dash]O), and absorbance of the isocyanate group and other chemical groups of the molecule were monitored over time. The ATR-FTIR findings showed that polymeric isocyanates pHDI and pIPDI may remain on the skin as unreacted species for many hours, with only 15-20% of the total isocyanate group disappearing in one hour, while smaller compounds octyl isocyanate and MDI rapidly disappear from the skin surface (80+% in 30 min). Isocyanates most likely leave the skin surface by diffusion predominantly, with minimal reaction with surface proteins. The significance of these findings and their implications for dermal exposure sampling and isocyanate skin decontamination are discussed.
Keywords
Isocyanates; Skin-absorption; In-vitro-studies; Animals; Animal-studies; Contact-dermatitis; Dermatitis; Dermatosis; Sensitization; Bronchial-asthma; Models; Sampling
Contact
Harvard School of Public Health, Exposure, Epidemiology & Risk Program, Landmark Center, West/404F, 401 Park Drive, Boston, MA 02215, USA
CODEN
JEMOFW
Publication Date
20060501
Document Type
Journal Article
Email Address
dbello@hsph.harvard.edu
Fiscal Year
2006
NTIS Accession No.
NTIS Price
Issue of Publication
5
ISSN
1464-0325
NIOSH Division
DART
Priority Area
Research Tools and Approaches: Exposure Assessment Methods
Source Name
Journal of Environmental Monitoring
State
OH; MA; CT
TOP