Quality check of safety data sheets for plant protection product co-formulants: hazard classification and coherence of the information. / Valutazione della qualità delle schede di sicurezza di coformulanti per prodotti fitosanitari: classificazione di pericolo e coerenza delle informazioni.

BACKGROUND: Hazard classification of chemicals can be defined as a logic-mathematical operation aimed at identifying the type and severity of the inherent hazards of a substance or a mixture. OBJECTIVES: The purpose of this study was to evaluate, in 134 safety data sheets (SDSs): i) the hazard classification and ii) its coherence with sections 9 (physical-chemical properties), 11 (toxicological properties) and 12 (ecological properties) of the SDSs. METHODS: Hazard classification and the information provided in sections 9, 11 and 12 of the SDSs have been evaluated against the criteria provided in annexes VI of the Dangerous Substance Directive, II and III of the Dangerous Preparations Directive, I and VI of the Regulation (EC) n. 1272/2008. RESULTS: Most of the analyzed SDSs of substances (62%) was associated to non-classified chemicals (61.4%), although 19.6% of them should have been classified. By contrast, 59.4% of classified substances (representing 38.6% of analyzed ones) were wrongly classified. Fifty-four %, 54% and 67% of suggested substances hazard classification were in line with sections 9 (physical-chemical properties), 11 (toxicological properties) and 12 (ecological properties). CONCLUSIONS: The proportion of hazard classification mistakes in SDS was significant, suggesting the need of more qualified experts to derive classification. The introduction of an ad hoc evaluation team, managed by a single, qualified specialist, could represent a solution to ensure the needed improvement of SDSs quality.

Electrochemical and spectroscopic behavior of iron(III) porphyrazines in Langmuir-Schafer films.

Thin films of a newly synthesized iron(III) porphyrazine, LFeOESPz ( L = ClEtO, OESPz = ethylsulfanylporphyrazine), have been deposited by the Langmuir-Schafer (LS) technique (horizontal lifting) on ITO or gold substrates. Before deposition, the floating films have been investigated at the air-water interface by pressure/area per molecule (pi/ A) experiments, Brewster angle microscopy (BAM) and UV-vis reflection spectroscopy (RefSpec). The complex reacts with water subphase (pH 6.2) forming the mu-oxo dimer, which becomes the predominant component of the LS films ( LS-Fe) as indicated by optical, IR, XPS, and electrochemical data. LS-Fe multilayers exhibit, between open circuit potential (OCP) and +0.90 V (vs SCE), two independent peak pairs with formal potentials, E surf (I) and E surf(II) of +0.56 V and +0.78 V, respectively. According to dynamic voltammetric and coulometric experiments the peak pair at +0.56 V is attributed to one-electron process at the iron(III) centers on the monomer, while the peak pair at +0.78 V is associated to a four-electron process involving mu-oxo-dimer oligomers. LS-Fe films prove to be quite stable electrochemically between OCP and +0.90 V. The electrochemical stability decreases, however, when the potential range is extended both anodically and cathodically outside these limits, due to formation of new species. Upon incubation with TCA solutions, LS-Fe films show remarkable changes in the UV-vis spectra, which are consistent with a significant mu-oxo dimer --> monomer conversion. Addition of TCA to the electrochemical cell using a LS-Fe film as working electrode, results in a linear increase of a cathodic current peak near -0.40 V as the TCA concentration varies in the 0.1-2.0 mM range. This behavior is interpreted in terms of TCA inducing a progressive change in the composition of the LS-Fe films in favor of the monomeric iron(III) porphyrazine, which is responsible for the observed increase in the cathodic current near -0.40 V.