Report on the Assessment of Contact Hypersensitivity to Dimethylamine Borane in Female BALB/c Mice (CAS No. 74-94-2)
Report Date: August 2012
The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings have not been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of the NTP or the U.S. Government.
Dimethylamine borane or boron-dimethylamine complex is a reducing agent widely used in the production of semiconductors, high-temperature printed circuit broads, thin metal film, power transistors, and floppy disks (Tsan et al., 2005; Kuo et al., 2006). Dermal exposure to DMA can induce irritation and corrosion to the skin and mucosa (BASF, 2004) in addition to depletion of epidermal nerves (Kuo et al., 2006). DMA easily decomposes to boric acid, borates, hydrogen, and dimethylamine, and dermal exposure to boric acid can induce erythema and desquamation (Tsan et al., 2005).
These studies were conducted to determine the sensitizing potential of DMA when applied dermally to female BALB/c mice. The local lymph node assay was performed to measure the sensitization potential of DMA at 5%, 10%, 25%, 37.5% and 50% (w/v) in the vehicle acetone: olive oil (4:1; AOO). DMA at 37.5% and 50% increased the draining lymph node cell proliferation in the LLNA, with one of the two studies reaching the three-fold level of lymph node cell proliferation when compared to the vehicle control. In the Irritancy Assay, significant increases in percent ear swelling were consistently observed at 37.5% DMA and above. However, the results from the Mouse Ear Swelling Test were negative, following sensitization with 10 - 50% DMA and challenge with either 25% or 50% DMA.
Overall, the results from these studies have demonstrated that DMA at 37.5 - 50% (w/v) produced significant increases in lymph node cell proliferation in the LLNA and in percent ear swelling in the IRR, while DMA had no effect in the MEST.
BASF. (2004). Material Safety Data Sheet of Dimethylamine Borane. Available online at http://www.basf.com/inorganics/pdf/MSDS/Boranes/DMAB.pdf.
Kuo H-C, Huang C-C, Chu C-C, Chu N-S (2006). Axonal polyneutopathy after acute dimethylamineborane intoxication. Arch Neurol. 63: 1009-1012.
Tsan Y.T., Peng K.Y., Huang D.Z., Hu W.H., & Yang D.Y. (2005). Case report: the clinical toxicity of dimethylamine borane. Enrivon Health Perspect Dec 113 (12): 1784-1786.