87-86-5

A white crystalline solid. Slightly soluble in water. Noncombustible. Toxic by inhalation, ingestion, and skin absorption. Used as a fungicide and as a wood preservative.

PENTACHLOROPHENOL(87-86-5) may react with strong oxidizing agents. Incompatible with strong bases, acid chlorides and acid anhydrides. Forms salts with alkaline metals. Solutions in oil cause natural rubber to deteriorate, but synthetic rubber may be used in equipment and for protective clothing .

Slightly soluble in water.

Dust or vapor irritates skin and mucous membranes, causing coughing and sneezing. Ingestion causes loss of appetite, respiratory difficulties, anesthesia, sweating, coma. Overexposure can cause death.

Pentachlorophenol (PCP) is a commercially produced bactericide, fungicide, and slimicide used primarily for the preservation of wood, wood products; and other materials. As a chlorinated hydrocarbon, its biological properties have also resulted in its use as an herbicide, and molluscicide. Two groups can be expected to encounter the largest exposures. One involves the small number of employees involved in the manufacture of PCP. All of these are presently under industrial health surveillance programs. The second and larger group are the formulators and wood theaters. Exposure, hygiene and industrial health practices can be expected to vary from the small theaters to the larger companies. The principal use as a wood preservative results in both point source water contamination at manufacturing and wood preservation sites and, conceivably, nonpoint source water contamination through runoff wherever there are PCP-treated lumber products exposing PCP to soil

Special Hazards of Combustion Products: Generates toxic and irritating vapors.

Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Medical observation is recommended for 24
48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy.

UN3155 Pentachlorophenol, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Reacts violently with strong oxidizers, acids, alkalies, and water.

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office. Incineration (600°to 900°C) coupled with acequate scrubbing and ash disposal facilities. Alternatively pentachlorophenol

White flakes or needles with a phenolic odor. At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor was detected were 23 and 9.3 μg/L, respectively. At 25 °C, the lowest concentration at which a taste was detected was 8 μg/L (Young et al., 1996).

.Insecticide; fungicide; herbicide.

Pentachlorophenol (PCP) is an odourless, white or light brown powder or crystal in appearance.  It is used as herbicide and fungicide. Pentachlorophenol is incompatible with strong  oxidising agents. Pentachlorophenol has a very sharp characteristic phenolic smell when  hot but very little odour at room temperature. Pentachlorophenol is a synthetic substance  made from other chemicals and does not occur naturally in the environment. Initially  pentachlorophenol was widely used as a wood preservative. It is now used industrially as  a wood preservative for power line poles, cross arms, fence post, etc.
Used as insecticide for terminate control; pre-harvest defoliant; general herbicide. Antimicrobial preservative and fungicide for wood, wood products, starches, textiles, paints, adhesives, leather, pulp, paper, industrial waste systems, building materials. Surface disinfectant.

Pentachlorophenol (PCP) is used for termite control, asa defoliant, and in the preservation of wood and wood products. It is an indoor air pollutant. It has been detected in timbers in the ppm range, causing contamination of air, surfaces, and materials in the homes. Its concentrations in blood samples have been reported in the range of sub-ppb to 110 μ/kg (Ruh et al. 1984). It has been detected in flue gas at 760–870°C (1400–1598°F) exit temperature from an incinerator at a concentration of 1.033 mg/m³ (Guinivan et al. 1985). The incinerator burned pentachlorophenol-treated wooden ammunition boxes and there was no afterburning. Methyl ethers of pentachlorophenol—pentachloroanisole and tetrachlorohydroquinone dimethyl ether —formed from microbial methylation of pentachlorophenol have been identified in the pg/m³ range in marine air samples from both the northern and southern hemispheres (Atlas et al. 1986)..

Pentachlorophenol is used to control termites and, as the laurate ester, wood boring insects. The ester and the sodium salt are used to protect wood from fungal rot and as general herbicides and defoliants. The sodium salt is also used as a general disinfectant.

ChEBI: A chlorophenol that is phenol substituted by 5 chloro groups.

Pentachlorophenol can be produced by the chlorination of phenol in the presence of AlCl3, or by hydrolysis of hexachlorobenzene with NaOH in methanol.

Fungicide, Herbicide, Slimicide, Wood preservative: Pentachlorophenol (PCP) is a commercially produced insecticide, fungicide, and slimicide. Since 1984 it has been restricted to certified applicators and is no longer available to the general public. It is primarily used to protect timber from fungal rot and wood-boring insects, but may also be used as a pre-harvest defoliant in cotton, a general pre-emergence herbicide, and as a biocide in industrial water systems. Not approved for use in EU countries. Not registered for use in the U.S. There are 48 global suppliers.

(The U.S. EPA lists 626 active and canceled/ transferredlabelsforthischemical) CHEM-TOL®; CHLON®; CHLOROPHEN®; CRYPTOGIL OL®; DOWCIDE® 7; DOWICIDE® 7; DOW PENTACHLOROPHENOL DP-2 ANTIMICROBIAL®; DURA TREET II®; DUROTOX®; EP 30®; FORPEN-50®; FUNGIFEN®; GLAZDPENTA ®; GRUNDIER ARBEZOL®; LAUXTOL®; LIROPREM®; ONTRACK WE HERBICIDE®; ORTHO TRIOX®; OSMOSE WPC®; PENTACHLOROPHENOL, DOWICIDE EC-7®; PENTACHLOROPHENOL, DP- 2®; PENTACON®; PENTA-KIL®; PENTA READY®; PENTASOL®; PENWAR®; PERATOX®; PERMACIDE®; PERMAGARD®; PERMASAN®; PERMATOX DP- 2®PERMATOX PENTA®; PERMITE®; POL NU®; PREVENTOL P®; PRILTOX®; SANTOBRITE®; SANTOPHEN®; SINITUHO®; TERM-I-TROL®; THOMPSON'S WOOD FIX®; WATERSHED WP®; WEEDONE®; WOODTREAT A®

The IARC has determined that there is limited evidence for carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals.

Biological. Under aerobic conditions, microbes in estuarine water partially dechlorinated pentachlorophenol to trichlorophenol (Hwang et al., 1986). The disappearance of
pentachlorophenol was studied in four aquaria with and without mud under aerobic and anaerobic conditions. Potential biological and/or chemical products identified include pentachloroanisole, 2,3,4,5-, 2,3,4,6- and 2,3,5,6-tetrachlorophenol (Boyle et al.,
Pentachlorophenol degraded in anaerobic sludge to 3,4,5-trichlorophenol which was further reduced to 3,5-dichlorophenol (Mikesell and Boyd, 1985). In activated sludge, only 0.2% of the applied amount was mineralized to carbon dioxide after 5 days (Freitag
Pentachlorophenol was statically incubated in the dark at 25°C with yeast extract and settled domestic wastewater inoculum. Significant biooxidation was observed but with a gradual adaptation over a 14-day period to achieve complete degradation at 5 mg/L substrate cultures. At a concentration of 10 mg/L, it took 28 days for pentachlorophenol to degrade completely (Tabak et al., 1981).
Melcer and Bedford (1988) studied the fate of pentachlorophenol in municipal activated sludge reactor systems that were operated at solids retention times of 10 to 20 days and hydraulic retention times of 120 days. Under these conditions, pentachloropheno

The insecticidal, antimicrobial and fungicidal properties of pentachlorophenol were discovered some time ago and the compound was first used in the 1930s for wood preservation and treatment. This and various industrial uses and its herbicidal and molluscicidal properties have led to its widespread use. Many countries have banned the use of pentachlorophenol as a wood preservative. Its main uses are now in cooling towers, paper mills and drilling muds (Litchfield and Rao, 1998). The compound has become distributed in various ecosystems, including those close to man’s living space. It is volatile and it may be absorbed via ingestion, inhalation or skin contact.
There exists a very large literature on the toxicology, metabolism, persistence and environmental effects and fate of pentachlorophenol, with well over 500 papers published in the last 30 years. Pentachlorophenol is rapidly and completely decomposed in sunlight; it is biodegraded in soil and plants and it is metabolised in animals. Pathways include dechlorination, methylation, oxidation, conjugation with sugars and sulfate and ring scission. The environmental fate and metabolism of pentachlorophenol were reviewed in 1986 by Engelhardt et al. (1986) and Renner and Muecke (1986). The pathways reported below are largely taken from these papers which are supported by more than 120 references. Other selected papers which cover important aspects are also quoted. The microbial degradation of the compound, particularly in relation to waste clean-up, has been reviewed recently (Litchfield and Rao, 1998).

Pentachlorophenol was metabolized in rats by conjugation with glucuronic acid and eliminated as the glucuronide. P450 catalyzed oxidative dechlorination also occurred to form tetrachlorohydroquinone, and this was conjugated to form a monoglucuronide representing 27% of the dose administered. Other metabolites have been reported, including isomeric tetrachlorophenols, tetrachlorocatechol and tetrachlororesorcinol. Trace amounts of benzoquinones were also noted. Metabolites in female rats were tetrachloromonophenols, diphenols, and hydroquinones.

At 20 °C (g/100 g solution): methanol (57.0), anhydrous ethanol (53.0), 95% ethanol (47.5), diethylene glycol monomethyl ether (48.0), pine oil (32.0), diethylene glycol monoethyl ether (30.0), diethylene glycol (27.5), 2-ethoxyethanol (27.0), dioxane (11.5), benzene (11.0), ethylene glycol (6.0), diesel oil (3.1), fuel oil (2.6) (Carswell and Nason, 1938).

At 20 °C (g/100 g solution): methanol (57.0), anhydrous ethanol (53.0), 95% ethanol (47.5), diethylene glycol monomethyl ether (48.0), pine oil (32.0), diethylene glycol monoethyl ether (30.0), diethylene glycol (27.5), 2-ethoxyethanol (27.0), dioxane (11.5), benzene (11.0), ethylene glycol (6.0), diesel oil (3.1), fuel oil (2.6) (Carswell and Nason, 1938).

Crystallise it twice from toluene/EtOH. Sublime it in vacuo.[Beilstein 6 IV 1025.]

Pentachlorophenol has the typical weak acidic properties of a phenol, readily forming the sodium salt. At physiological pH a major proportion is ionised and the metabolism (but not necessarily the mobility and absorption) of pentachlorophenol and its sodium salt should be very similar. The laurate ester, being lipophilic, is absorbed more readily than the phenate ion and it is also more volatile. However, the ester should be readily hydrolysed in dilute base to pentachlorophenol and lauric acid and by estersases in vivo to the same products. Thus the metabolism of the three forms may be considered together.
Pentachlorophenol is rapidly degraded under conditions of aqueous photolysis in W light and sunlight (Engelhardt et al., 1986). Products detected (Scheme 1) include the reductive dechlorination products 2,3,4,6- and 2,3,5,6-tetrachlorophenol (2 and 3) and trichlorophenols. Ring chlorine atoms were displaced by hydroxyl groups to afford 2,3,5,6-tetrachlorohydroquinone (4), tetrachlorocatechol (5) and tetrachlororesorcinol( 6). The hydroquinone (4) was very rapidly decomposed in air. Irradiation of each of 4, 5 and 6 afforded trichlorobenzenediols, trichloroquinones and 2,3-dichloromaleic acid (7).
Hydroquinone 4 oxidised in the dark (and in light) to 2,3,5,6- tetrachloro-l,4-benzoquinone (8), the 2-hydroxy analogue (9), the dichlorohydroxybenzoquinone (10) and the maleic acid (7). The latter eventually affords CO₂ and HCl.
Exposure of an aqueous solution of the sodium salt to sunlight gave small amounts of octachlorodibenzodioxin but none of the extremely toxic 2,3,7,8-tetrachloro derivative could be detected. Much of the original work on the photolysis of pentachlorophenol was reported by Wong and Crosby (1978).

The toxicology has been addressed in a recent risk assessment (119). Acutely, pentachlorophenol was reported to have LD₅₀ values in the rat of 12 mg/kg (inhalation) and 146 mg/kg (M)–175 mg/kg (F) by oral gavage. More detailed studies of the toxicology of pentachlorophenol have been compromised by the toxicity of impurities present in most of the earlier samples used in the evaluation process.Although a number of toxicity studies have been conducted with both known impurities and TCHQ, it is often difficult to know whether animal experiments are valid for human health risk assessment. Nevertheless, it appears that the main target organ of purified TCP in animals is the liver.
This toxicity was manifested as liver inflammation, increased relative weight, and increased serum alkaline phosphatase. The estimated chronic NOEL in the dog for these effects was 0.15 mg/kg/day, from a 1-year study, based on a LOEL of 1.5 mg/kg/day. In the rat, a significantly increased incidence of mesotheliomas (p<0.05) and nasal carcinomas in males was reported at the highest dose tested, ～60 mg/kg/day.