A QSAR/QSTR Study on the Environmental Health Impact by the Rocket Fuel 1,1-Dimethyl Hydrazine and its Transformation Products

Abstract

QSAR/QSTR modelling constitutes an attractive approach to preliminary assessment of the impact on environmental health by a primary pollutant and the suite of transformation products that may be persistent in and toxic to the environment. The present paper studies the impact on environmental health by residuals of the rocket fuel 1,1-dimethyl hydrazine (heptyl) and its transformation products. The transformation products, comprising a variety of nitrogen containing compounds are suggested all to possess a significant migration potential. In all cases the compounds were found being rapidly biodegradable. However, unexpected low microbial activity may cause significant changes. None of the studied compounds appear to be bioaccumulating.Apart from substances with an intact hydrazine structure or hydrazone structure the transformation products in general display rather low environmental toxicities. Thus, it is concluded that apparently further attention should be given to tri- and tetramethyl hydrazine and 1-formyl 2,2-dimethyl hydrazine as well as to the hydrazones of formaldehyde and acetaldehyde as these five compounds may contribute to the overall environmental toxicity of residual rocket fuel and its transformation products.

N-Nitrosodimethylamine Formation from Hydrazine Compounds on Ozonation

“…Figure 1 shows the chemical structures of six target compounds, all of which have N,N-dimethylhydrazino functional groups. Formaldehyde dimethylhydrazone (FDH) (99.9%), 1-formyl-2,2-dimethylhydrazine (FDMH) (99.6%), and tetramethyltetrazene (TMT) (98.0%) are transformation products of UDMH (Carlsen et al 2008). FDH, FDMH, TMT, 1,1-dimethylsemicarbazide (DMSC) (98.5%), and 2,2-dimethylhydrazine carboxylic acid methyl ester (DHME) (99.8%) were synthesized on commission by Tokyo Kasei Industry (Tokyo, Japan).…”

Determination of 1-methyl-1H-1,2,4-triazole in soils contaminated by rocket fuel using solid-phase microextraction, isotope dilution and gas chromatography–mass spectrometry

“…Contamination of soil by highly toxic rocket fuel unsymmetrical dimethylhydrazine (UDMH) and its transformation products causes many health risks, especially for human population and ecosystem of territories close to take-off routes of heavy rockets "Proton", "Dnepr" and "Cyclone" launched from Baikonur cosmodrome [1]. Most toxic UDMH transformation products are N-nitrosodimethylamine, dimethylamine, tetramethyltetrazene and 1-methyl-1H-1,2,4-triazole (MTA) [2].…”

“…High concentrations of MTA in soils are also caused by it's high boiling point (177-178°C) [5]. MTA has low logK ow ( À0.21), very high water solubility and migration potential [1]. Experimentally determined lethal dose for MTA at its intravenous, intraperitoneal and peroral administrations are 510 720, 750 740 and 1020 760 mg kg À 1 body weight, respectively [6,7].…”

Toxic splash: Russian rocket stages dropped in Arctic waters raise health, environmental and legal concerns

“…A follow-up study, published the next year, examined 18 'transformation products' that are formed directly from UDMH when it is released into the environment or through subsequent processes (Carlsen, Kenessov, & Batyrbekova, 2008). It reported that:…”

“…Moreover, some of these substances persist longer in the environment than UDMH; for example, 1-formyl 2,2-dimethylhydrazine has a half-life of 2,220 years in lakes (Carlsen et al, 2008). It is therefore possible that UDMH released into the air or water, or landing on sea ice, could be transformed into chemical derivatives posing risks to human health and the environment that are not only serious but longer lasting than those posed by UDMH alone.…”