Azocyclotin

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

0.1 [mg/m3], as Sn

0.2 [mg/m3], as Sn

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 18,000(SRC), determined from a log Kow of 5.3(2) and a regression-derived equation(3), indicates that azocyclotin is expected to be immobile in soil(SRC). Volatilization of azocyclotin from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.1X10-12 atm-cu m/mole(SRC), derived from its vapor pressure, 4.5X10-13 mm Hg(2), and water solubility, 1.2X10-1 mg/l(2). Azocyclotin is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 18,000(SRC), determined from a log Kow of 5.3(2) and a regression-derived equation(3), indicates that azocyclotin is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.1X10-12 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4), derived from its vapor pressure, 4.5X10-13 mm Hg(2), and water solubility, 1.2X10-1 mg/l(2). The pKa of azocyclotin is 5.36(2), indicating that this compound will partially exist in the protonated form in the environment and cations generally adsorb to organic carbon and clay more strongly than their neutral counterparts(5). According to a classification scheme(6), an estimated BCF of 2,400(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low very high(SRC). Using a fresh water microcosm, azocyclotin was observed to be rapidly hydrolyzed to cyhexatin (tricyclohexyltinhydroxide) in a matter of days(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), azocyclotin, which has a vapor pressure of 4.5X10-13 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase azocyclotin may be removed from the air by wet and dry deposition(SRC).

Organotin compounds produce neurotoxic and immunotoxic effects. Organotins may directly activate glial cells contributing to neuronal cell degeneration by local release of pro-inflammatory cytokines, tumor necrosis factor-_, and/or interleukins. They may also induce apoptosis by direct action on neuronal cells. Organotin compounds stimulate the neuronal release of and/or decrease of neuronal cell uptake of neurotransmitters in brain tissue, including aspartate, GABA, glutamate, norepinephrine, and serotonin. This may be either a contributing factor to or result of the neuronal cell loss. The immunotoxic effects of organotins are characterized by thymic atrophy caused by the suppression of proliferation of immature thymocytes and apoptosis of mature thymocytes. Organotin compounds are believed to exert these effects by suppressing DNA and protein synthesis, inducing the expression of genes involved in apoptosis (such as nur77), and disrupting the regulation of intracellular calcium levels, giving rise to the uncontrolled production of reactive oxygen species, release of cytochrome c to the cytosol, and the proteolytic and nucleolytic cascade of apoptosis. The suppression of proliferation of immature thymocytes further results in the suppression of T-cell-mediated immune responses. Organotins are also endocrine disruptors and are believed to contribute to obesity by inappropriate receptor activation, leading to adipocyte differentiation. Inorganic tin triggers eryptosis, contributing to tin-induced anemia. (L308, A182, A184)

The Koc of azocyclotin is estimated as 18,000(SRC), using a log Kow of 5.3(1)and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that azocyclotin is expected to be immobile in soil. The pKa of azocyclotin is 5.36(1), indicating that this compound will partially exist in the protonated form in the environment and cations generally adsorb to organic carbon and clay more strongly than their neutral counterparts(4).

An estimated BCF of 2,400 was calculated for azocyclotin(SRC), using a log Kow of 5.3(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is very high(SRC).

The Henry's Law constant for azocyclotin is estimated as 2.15X10-12 atm-cu m/mole(SRC) derived from its vapor pressure, 4.5X10-13 mm Hg(1), and water solubility, 1.2X10-1 mg/l(1). This Henry's Law constant indicates that azocyclotin is expected to be essentially nonvolatile from water surfaces(2). Azocyclotin is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).