チオシアン酸

Other Classes -> Organic Acids

Ionic Liquids

Colorless gas or white solid (depends on degree of polymerization); [Merck Index] Colorless liquid; mp = 5 deg C; [ICSC]

COLOURLESS LIQUID.

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P317, P321, P330, P362+P364, and P501 (click each P-code to see the statement)

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P317, P321, P330, P362+P364, and P501 (click each P-code to see the statement)

Acute toxicity - category 4

Acute Tox. 4 *

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Refer for medical attention .

Personal protection: filter respirator for acid gases and vapours adapted to the airborne concentration of the substance. Collect leaking and spilled liquid in covered containers as far as possible. Carefully collect remainder. Then store and dispose of according to local regulations.

In cases of thiocyanate exposure, get fresh air and medical attention. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. If swallowed, do not induce vomiting but give large quantities of water. Immediately flush skin with plenty of water for at least 15 minutes in case of exposure to skin or the eyes. (L217)

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)

Thiocyanates are known to affect the thyroid glands, reducing the ability of the gland to produce hormones that are necessary for the normal function of the body. Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma and death. (L191)

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)

The substance can be absorbed into the body by inhalation of its vapour and by ingestion.

Oral (L191); inhalation (L191) ; dermal (L191)

Inhalation (L96) ; oral (L96) ; dermal (L96)

Thiocyanate (sulphocyanate or SCN) is believed to be a goitrogenic compound. It is a competitive inhibitor of the human thyroid sodium/iodide symporter NIS. Thus, the adverse effects of thiocyanate overload are especially noticeable when iodine availability is low. Intake of goitrogenic substances causes an adaptive increase in T3‰ЫЄs binding to brain nuclear receptors and in the activity of type II 5'-deiodinase, which generates T3 from T4. This altered function and availability of T3 is detrimental to the developing brain. Thiocyanate is also known to modulate activity of mammalian peroxidases. For instance, eosinophil peroxidase has been implicated in promoting oxidative tissue damage in a variety of inflammatory conditions, including asthma. Thiocyanate also acts as inhibitor to carbonic anhydrase, which catalyzes the rapid conversion of carbon dioxide to bicarbonate and protons. (A139, A143, A149) 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)

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)

Symptoms of thiocyanate exposure include rapid, deep breathing and shortness of breath, followed by convulsions (seizures) and loss of consciousness. (L191)

Cyanide poisoning is identified by rapid, deep breathing and shortness of breath, general weakness, giddiness, headaches, vertigo, confusion, convulsions/seizures and eventually loss of consciousness. (L96, L97)

No indication of carcinogenicity to humans (not listed by IARC).

No indication of carcinogenicity to humans (not listed by IARC).

Guanidine Thiocyanate: LD50: 375 mg/kg (Oral, Rat), LD50: 2000 mg/kg (Dermal, Rabbit) (L218) Potassium Thiocyanate: LD50: 854 mg/kg (Oral, Rat) (L219) Ammonium Thiocyanate: LD50: 750 mg/kg (Oral, Rat), LD50: 500 mg/kg (Oral, Mouse) (L220)

LD50: 500 mg/kg (Oral, Mouse) (L558) LD50: 500 mg/kg (Intraperitoneal, Mouse) (L558)

0.0002

SCREEN Current

0.0006

PPRTV Current

Thiocyanic Acid

PDF Document

2012

1.60e+01

2.30e+02

4.00e+00

2.00e+00

2.00e-04

Volatile

4.70e+01

7.00e+02

1.20e+01

2.00e+00

2.00e-04

Volatile

Thiocyanates can appear in the body after metabolization of cyanides by rhodanese. When thiocyanates enter the body, they normally breaks down in aqueous solution to yield sulfate ions. However, thiocyanates are also found in the thyroid fluids. Immediately following exposure to thiocyanate containing solutions, the cystic fibrosis conductance regulator Cl‰ЫТ channel exhibits high unitary SCN‰ЫТ conductance and anomalous mole fraction behaviour. Thiocyanates is normally excreted in urine. (A140, A142, A143, A144) Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)

Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)

Exposure occurs from breathing air and drinking water, touching soil or water containing thiocyanate, or eating foods that contain thiocyanate. Thiocyanates are present in water primarily because of discharges from coal processing, extraction of gold and silver, and mining industries. Thiocyanate is the major product formed from cyanide that passes into the body as the body attempts to rid itself of cyanide, thus exposure to cyanide also results in exposure to thiocyanate. (L191)