We are just at the beginning of studying these surfactants. Neither the pesticide companies nor the companies using them in hydro-fracking & oil dispersion are saying what they are, claiming proprietary secrecy. 

Quoted from Abstract:

> Organosiloxane surfactants, the most novel class of non-ionic surfactants in agrochemical formulations, have been widely used around hives or in honey bee foraging areas as pesticide spray adjuvants.

> Detailed component information is not given in most commercial adjuvants. Hydrolyzed products or alternative degradates of organosiloxane surfactants also can be produced during storage or usage. To fully understand and assess risk of organosiloxane surfactants to honey bee health requires disclosure of structural identities and amounts of individual components, including synthetic impurities and degradates, in commercial adjuvants.

> Here a LC-MS (Liquid Chromatogram coupled to Mass Spectrometry) strategy for structural identification of organosiloxanes in commercial adjuvants is introduced. The structure of the siloxane moiety is identified using an isotope ratio rule. A single charged/double charged mass ion ratio is calculated to distinguish single or double polyalkylene oxide chains in the hydrophilic portion of the molecule. Using a database developed for this study, which includes the mass ion information of all potential structures, allows assignment of the organosiloxane surfactant structure including its side-chain links and cap-groups.

> By this LC-MS method individual organosiloxane surfactant compounds present in five commonly used commercial adjuvants have been identified by integrating their chromatographic and mass spectrometric characteristics. As a result, hydroxy(polyethyleneoxy)propyl-heptamethyltrisiloxane, methoxy(polyethyleneoxy)propyl-heptamethyltrisiloxane, acetoxy(polyethyleneoxy)propyl-heptamethyltrisiloxane were found as the most common components. The identifications were validated by 1HNMR, 13CNMR, and HMQC (heteronuclear multiple bond coherence) spectrums of respective HPLC fractions that were pooled from multiple adjuvant injections. Moreover, hydrolyzed products of organsilicone surfactants were also identified. 

>This information will allow for the first time development of an analytical method to quantify organosiloxane residues in bees and other hive samples and environmental matrices.

Chen, J., J.L. Frazier, M.T. Frazier & C.A. Mullin, 2012

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