Seasonal Difference in Percutaneous Absorption of N,N‐Dimethylformamide as Determined Using Two Urinary Metabolites

Abstract

summer were attributed to increased percutaneous absorption of DMF resulting from the increased amount of water-soluble DMF absorbed by sweaty skin caused by the increased summertime room temperature and humidity. (J Occup Health 2014; 56: 252-259)

Occupational Exposure to N,N-Dimethylformamide in the Summer and Winter

“…The workers all engaged in one or more of four different jobs: the formulation of resin products, finishing the formulated product, inspection of the manufactured products, and packing of the final products for marketing. Their workrooms were located in a different place distant from the main production lines which emanated relatively high levels of DMF, as described in our previous study 23 ) . Their workload was regarded as light work without discernible perspiration.…”

“…The analytical methods used in the present study were as described 23 ) . Briefly, DMF vapor collected in the diffusive passive sampler was analyzed with a combined gas chromatograph-mass spectrometer (GC-MS) equipped with an HP-WAX capillary column (30-m-long, 1-μm-thick film, cross-linked polyethylene; Hewlett Packard, Palo Alto, CA, USA) and with an automatic liquid sample injector (7683 Series Injector, Agilent Technologies, Santa Clara, CA, USA).…”

“…Our previous study 23 ) showed that workers’ urinary levels of NMF and AMCC were significantly higher in the summer than in the winter, suggesting increased skin absorption of DMF due to the summertime increase in room temperature and relative humidity 23 ) . Drexler et al 24 ) demonstrated workers’ increased internal exposure to carbon disulfide (CS 2 ) resulting from more intensive skin contact and physical work.…”

“…We conducted the present study to further examine our hypothesis 23 ) that the skin absorption of DMF vapor was enhanced in the summer compared to the uptake of DMF vapor through the lungs, due to the summertime increase in room temperature and relative humidity. For this examination, we recruited another group of workers who were working without respiratory protective masks (in contrast to the previously reported respirator-wearing workers directly handling DMF in the same resin-product manufacturing factory) 23 ) , and we used the same RIE index for DMF-exposed workers as that demonstrated for CS 2 -exposed workers by Drexler et al 24 ) .…”

Human Biomonitoring Initiative (HBM4EU): Human Biomonitoring Guidance Values Derived for Dimethylformamide

“…DMF absorption has been well-studied in humans (workers and volunteers); absorption via inhalation is high, with 60-90% of the inhaled dose retained in the respiratory tract [21,22]. Dermal absorption in humans from direct contact is also very high (up to 40%, depending on temperature and humidity) [23][24][25]. In the study by Nomiyama et al (2001), in which the authors evaluated the difference between the absorption of DMF vapor by dermal and inhalation routes, it was estimated that skin and lung absorption contributed for 40.4% and 59.6% of total absorption, respectively [26].…”