46
T3D0045
Pentachlorophenol
Pentachlorophenol (PCP) is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names. It can be found in two forms: PCP itself or as the sodium salt of PCP, which dissolves easily in water. Short-term exposure to large amounts of PCP can cause harmful effects on the liver, kidneys, blood, lungs, nervous system, immune system, and gastrointestinal tract. Elevated temperature, profuse sweating, uncoordinated movement, muscle twitching, and coma are additional side effects. Contact with PCP (particularly in the form of vapor) can irritate the skin, eyes, and mouth. Long-term exposure to low levels such as those that occur in the workplace can cause damage to the liver, kidneys, blood, and nervous system. Finally exposure to PCP is also associated with carcinogenic, renal, and neurological effects. The U.S. Environmental Protection Agency Toxicity Class classifies PCP in group B2 (probable human carcinogen).
87-86-5
992
C6HCl5O
263.847000
Colorless (pure) or dark gray to brown (inpure) solid.
174°C
309-310°C
0.014 mg/mL at 25°C
Oral (L127) ; inhalation (L127) ; dermal (L127)
Pentachlorophenol is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.
Pentachlorophenol is efficiently absorbed following inhalation, oral, and dermal exposure, then binds to plasma proteins and is distributed to the liver, lungs, kidneys, blood, fat tissues, and brain. Extensive plasma protein binding of pentachlorophenol may account for its low degree of metabolism. Metabolism of pentachlorophenol occurs in the liver, and the major pathways are conjugation to form the glucuronide and oxidative dechlorination to form tetrachlorohydroquinone (TCHQ). Pentachlorophenol and its metabolites are excreted mainly in the urine. (L127)
LD50: 27 mg/kg (Oral, Rat) (T26)
LD50: 96 mg/kg (Dermal, Rat) (T26)
LD50: 56 mg/kg (Intraperitoneal, Rat) (T26)
LD50: 58 mg/kg (Subcutaneous, Rat) (T26)
2B, possibly carcinogenic to humans. (L135)
Pentachlorophenol is a restrictively used pesticide and is used industrially as a wood preservative for utility poles, railroad ties, and wharf pilings. (L127)
Acute Oral: 0.005 mg/kg/day (L134)
Intermediate Oral: 0.001 mg/kg/day (L134)
Chronic Oral: 0.001 mg/kg/day (L134)
Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.
Exposure to high levels of pentachlorophenol can cause the cells in the body to produce excess heat, resulting in a very high fever, profuse sweating, and difficulty breathing. Contact with pentachlorophenol, particularly in the form of vapor can irritate the skin, eyes, and mouth. (L127, L128)
If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.
2009-03-06T18:57:58Z
2014-12-24T20:20:58Z
UDP-glucuronosyltransferase 1-1 (P22309)
UDP-glucuronosyltransferase 1-4 (P22310)
Sulfotransferase 1A1 (P50225)
Sulfotransferase 1A2 (P50226)
Sulfotransferase 1A3/1A4 (P50224)
Cytochrome P450 3A4 (P08684)
Cytochrome P450 3A7 (P24462)
(L127)
http://en.wikipedia.org/wiki/pentachlorophenol
C02575
17642
CPD-10489
D010416
Pentachlorophenol
PCI
1132
true
UDP-glucuronosyltransferase 1-1 (P22309)
UDP-glucuronosyltransferase 1-4 (P22310)
Sulfotransferase 1A1 (P50225)
Sulfotransferase 1A2 (P50226)
Sulfotransferase 1A3/1A4 (P50224)
Cytochrome P450 3A4 (P08684)
Cytochrome P450 3A7 (P24462)
(L127)
OC1=C(Cl)C(Cl)=C(Cl)C(Cl)=C1Cl
C6HCl5O
InChI=1S/C6HCl5O/c7-1-2(8)4(10)6(12)5(11)3(1)9/h12H
InChIKey=IZUPBVBPLAPZRR-UHFFFAOYSA-N
266.337
263.847003189
Exogenous
Solid
5.12
HMDB41974
CHEMBL75967
967