Ethyl thiocyanate

(Non-Specific -- Pesticide, Liquid, n.o.s.) Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Wear positive pressure breathing apparatus and special protective clothing. Move container from fire area if you can do it without risk. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter the material.

(Non-Specific -- Pesticide, Liquid, n.o.s.) Do not touch spilled material; stop leak if you can do so without risk. Use water spray to reduce vapors. For small spills, absorb with sand or other noncombustible absorbent material and place into containers for later disposal. For large spills, dike far ahead of spill for later disposal. (EPA, 1998)

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.

1.5 [mg/m3]

17 [mg/m3]

84 [mg/m3]

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)

Antidotes to cyanide poisoning include hydroxocobalamin and sodium nitrite, which release the cyanide from the cytochrome system, and rhodanase, which is an enzyme occurring naturally in mammals that combines serum cyanide with thiosulfate, producing comparatively harmless thiocyanate. Oxygen therapy can also be administered. (L97)

Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma, seizures, apnea, cardiac arrest and death. Chronic inhalation of cyanide causes breathing difficulties, chest pain, vomiting, blood changes, headaches, and enlargement of the thyroid gland. Skin contact with cyanide salts can irritate and produce sores. (L96, L97)

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 15(SRC), determined from a structure estimation method(2), indicates that ethyl thiocyanate is expected to have very high mobility in soil(SRC). Volatilization of ethyl thiocyanate from moist soil surfaces may be important(SRC) given an estimated Henry's Law constant of 5.82X10-5 atm-cu m/mole(SRC), using a fragment constant estimation method(3). The potential for volatilization of ethyl thiocyanate from dry soil surfaces may exist(SRC) based on an estimated vapor pressure of 5 mm Hg(SRC), determined from a fragment constant method(4). Biodegradation data for ethyl thiocyanate are not readily available(SRC).

AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 15(SRC), determined from a structure estimation method(2), indicates that ethyl thiocyanate is not expected to adsorb to suspended solids and sediment in water(SRC). Ethyl thiocyanate may volatilize from water surfaces(3,SRC) based on an estimated Henry's Law constant of 5.82X10-5 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Estimated volatilization half-lives for a model river and model lake are 16.8 hours and 191.1 hours, respectively(3,SRC). According to a classification scheme(5), an estimated BCF of 5.0(3,SRC), from an estimated log Kow of 1.22(6,SRC), suggests that bioconcentration in aquatic organisms is low(SRC). Biodegradation data for ethyl thiocyanate are not readily available(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), ethyl thiocyanate, which has an estimated vapor pressure of 4.8 mm Hg at 25 °C(2,SRC), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase ethyl thiocyanate is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be about 2.2 days(3,SRC).

Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)

Using a structure estimation method based on molecular connectivity indices(1), the Koc for ethyl thiocyanate can be estimated to be about 15(SRC). According to a recommended classification scheme(2), this estimated Koc value suggests that ethyl thiocyanate is expected to have very high mobility in soil(SRC).

Food-borne goitrogens are often characterized by the presence of sulfur and most are thiocyanates or closely related compounds. Because of their widespread occurrence in Cruciferae, eg, cabbage, kale, onions, cress, broccoli, cauliflower, rutabaga, turnip & radish, goitrogens are among the most common and longest recognized substances of toxic nature in the human food supply. ... It has ... been demonstrated that the quantity of the precursor found in plant materials is related to the available sulfur in the soil. /Goitrogens/

All /aliphatic thiocyanates/ have an appreciable percutaneous toxicity, although this is not regarded as an important hazard with the concentrations usually employed in agriculture. Primary irritation of skin and eyes due to local contact, however, is not a negligible hazard, and the undiluted liquids may produce very severe cutaneous reactions ... /Aliphatic thiocyanates/

... important qualitative distinctions are recognized among the various organic thiocyanates. ... ethyl ... thiocyanate .. /is a/ rapidly acting poison of high potency.

Food-borne goitrogens are often characterized by the presence of sulfur and most are thiocyanates ... /Goitrogens/ are among the most common and longest recognized substances of toxic nature in the human food supply. /Goitrogens/

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Ethylthiocyanate is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 10,000 lbs.