PRODUCTS

CYCLOHEXYLAMINE

Cyclohexylamine is an organic compound, belonging to the aliphatic amine class. It is a colorless liquid, although, like many amines, samples are often colored due to contaminants. It has a fishy odor and is miscible with water. Like other amines, it is a weak base, compared to strong bases such as NaOH, but it is a stronger base than its aromatic analog, aniline.
It is a useful intermediate in the production of many other organic compounds (e.g cyclamate)

CYCLOHEXYLAMINE

CAS No. : 108-91-8
EC No. : 203-629-0

Synonyms:
Cyclohexylamine; Aminocyclohexane; Aminohexahydrobenzene; Hexahydroaniline; Hexahydrobenzenamine; CYCLOHEXYLAMINE; CYCLOHEXYL AMINE; CYCLO HEXYLAMINE; sikloheksilamin; siklohegzilamin; sıkloheksılamın; sıklohegzılamın; Cyclohexanamine; 108-91-8; Aminocyclohexane; Hexahydroaniline; Hexahydrobenzenamine; Aminohexahydrobenzene; Cyclohexyl amine; 1-Cyclohexylamine; 1-Aminocyclohexane; Aniline, hexahydro-; Benzenamine, hexahydro-; Aminocylcohexane; Cyclohexylamines; cyclohexyl-amine; UNII-I6GH4W7AEG; 1-AMINO-CYCLOHEXANE; CCRIS 3645; HSDB 918; cyclohexaneamine; Cyclohexylamine.HCl; EINECS 203-629-0; UN2357; Cyclohexylamin; AI3-15323; CHEBI:15773; Cyclohexylamine [UN2357] [Corrosive]; Cyclohexylamine, 99%; Cyclohexylamine [UN2357] [Corrosive]; DSSTox_CID_3996; CAS-108-91-8; HAI; cylohexylamine; cyclohexylarnine; cyclo-hexylamine; cyclohexane-amine; n-cyclohexylamine; cyclohexanyl amine; Hexahydro-Aniline; monocyclohexylamine; 4-Cyclohexylamine; Cyclohexylamine,(S); Hexahydro-Benzenamine; Cyclohexanamine, 9CI; CyNH2; ACMC-1BUGG; Cyclohexylamine, 99.5%; $l^{1}-azanylcyclohexane; bmse000451; EC 203-629-0; 4-12-00-00008 (Beilstein Handbook Reference); Cyclohexylamine, ReagentPlus(R), 99%; MCULE-7654331405; UN 2357; VS-0326; Aminocyclohexane pound>>Hexahydroaniline; KS-00000X91; Phosphoramide mustard cyclohexamine salt; Phosphorodiamidic acid, N,N-bis(2-chloroethyl)-, compd. with cyclohexanamine (1:1); N,N-bis (2-chloroethyl)phosphorodiamidic acid compound with cyclohexanamine (1:1); N,N-Bis(2-chloroethyl) phosphorodiamidic acid, cyclohexylammonium salt; Phosphorodiamidic acid, N,N-bis(2-chloroethyl)-, cyclohexylamine salt NCGC00247889-01; AM802905; BP-21278; CAS_108-91-8; Cyclohexylamine 1000 microg/mL in Methanol; Cyclohexylamine, ReagentPlus(R), >=99.9%; Cyclohexylamine; Aminocyclohexane; Aminohexahydrobenzene; Hexahydroaniline; Hexahydrobenzenamine; CYCLOHEXYLAMINE; CYCLOHEXYL AMINE; CYCLO HEXYLAMINE; sikloheksilamin; siklohegzilamin; Cyclohexanamine; 108-91-8; Aminocyclohexane; Hexahydroaniline; Hexahydrobenzenamine; Aminohexahydrobenzene; Cyclohexyl amine; 1-Cyclohexylamine; 1-Aminocyclohexane; Aniline, hexahydro-; Benzenamine, hexahydro-; Aminocylcohexane; Cyclohexylamines; cyclohexyl-amine; Phosphorodiamidic acid, N,N-bis(2-chloroethyl)-, compd. with cyclohexanamine(1:1) (9CI); N,N-Bis(2-chloroethyl)phosphorodiamidic acid--cyclohexanamine (1/1); Phosphorodiamidic acid,N-bis(2-chloroethyl)-, cyclohexylamine salt; Phosphorodiamidic acid,N-bis(2-chloroethyl)-, compd. with cyclohexylamine; Cyclohexanamine N,N-bis(2-chloroethyl)phosphorodiamidate; Phosphorodiamidic acid,N-bis(2-chloroethyl)-, compd. with cyclohexylamine(1:1); Cytoxyl alcohol cyclohexylamine salt; Cytoxyl alcohol cyclohexylammonium salt; Cytoxyl alcohol compd. with cyclohexylamine; N,N-Bis(2-chloroethyl)-N'-(3-hydroxypropyl) phosphorodiamidate cyclohexylammonium salt; N,N-Bis(2-chloroethyl)-N'-3-hydroxypropyl phosphorodiamidic acid;Phosphorodiamidic acid, N,N-bis(2-chloroethyl)-N'-(3-hydroxypropyl)-, cyclohexylamine salt; Cytoxal alcohol cyclohexylamine salt; Phosphorodiamidic acid,N-bis(2-chloroethyl)-N'-(3-hydroxypropyl)-, cyclohexylamine salt; Cytoxyl Alcohol Cyclohexylamine Salt; Ziram, cyclohexylamine complex; Zinc, dimethyldithiocarbamate cyclohexylamine complex; (Cyclohexylamine)bis(dimethyldithiocarbamato-S,S')zinc; Zinc, bis(dimethyldithiocarbamato)-, compd. with cyclohexylamine; Butyl(Dimethyl)Silyl]Oxy}Phenyl)Cyclohexylamine; Cyclohexylamine Benzoate; Aminocyclohexane; 1-Aminocyclohexane; 1-AMINO-CYCLOHEXANE; 1-Cyclohexylamine; 203-629-0 [EINECS]; Aminocyclohexane; aminohexahydrobenzene; Aniline, hexahydro-; Benzenamine, hexahydro-; Cyclohexanamin [German] [ACD/IUPAC Name]; Cyclohexanamine [French] [ACD/Index Name] [ACD/IUPAC Name]; cyclohexyl amine; Cyclohexylamine [Wiki]; Hexahydroaniline; I6GH4W7AEG; Magenta-GlcA [Trade name]; N-Cyclohexylamine; CHA; CHA-60; cha[qr]; Cyclohexylamin; AURORA KA-7609; CYCLOHEXYLAMINE; AMINOCYCLOHEXANE; HEXAHYDROANILINE; cyclohexaneamine; hexahydro-anilin

Cyclohexylamine

Preparation
Cyclohexylamine is produced by two routes, the main one being the complete hydrogenation of aniline using some cobalt- or nickel-based catalysts:
C6H5NH2 + 3 H2 → C6H11NH2
It is also prepared by alkylation of ammonia using cyclohexanol.

Applications
Cyclohexylamine is used as an intermediate in synthesis of other organic compounds. It is the precursor to sulfenamide-based reagents used as accelerators for vulcanization. It is a building block for pharmaceuticals (e.g., mucolytics, analgesics, and bronchodilators). The amine itself is an effective corrosion inhibitor. Some sweeteners are derived from this amine, notably cyclamate. The herbicide hexazinone and the anesthetic hexylcaine are derived from cyclohexylamine.

Toxicity
LD50 (rat; p.o.) = 0.71 ml/kg
It is corrosive. Cyclohexylamine is listed as an extremely hazardous substance as defined by Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act. It has been used as a flushing aid in the printing ink industry.[6]
The National Institute for Occupational Safety and Health has suggested workers not be exposed to a recommended exposure limit of over 10 ppm (40 mg/m3) over an eight-hour workshift.

Cyclohexylamine showed dose dependent kinetics after administration of single oral doses of 35, 200, or 500 mg/kg in rats, with a reduction in plasma clearance from 37 to 24 ml/min/kg, an increase in apparent half-life from 11.8 to 12 hr, and an increased area under the testicular concentration vs time curve. Saturation of cyclohexylamine uptake by rat renal cortical slices in vitro and of renal tubular secretion in vivo occurred at concentrations and doses comparable to the oral dose studies. Cyclohexylamine clearance from a 10 mg/kg infusion was 2.58 + or - 1.13 ml/min and from a 200 mg/kg infusion, 2.49 + or - 1.65 ml/min. The cyclohexylamine to inulin clearance ratios were 2 at a dose of 10 mg/kg and 1.23 at a dose of 200 mg/kg. During chronic dietary administration the concentrations of cyclohexylamine in the plasma and testes showed a pronounced diurnal variation in rats, reaching a peak concentration at the end of the dark cycle at 6 AM (6.3 + or - 1.5 ug/ml in plasma an 45.7 + or - 3.4 ug/g in testes). The lowest concentrations of cyclohexylamine were at 9 PM (1.5 + of - 0.5 ug/ml in plasma and 10.9 + or - 3.6 ug/g in testes). The steady state plasma clearance was 33 ml/min/kg. The concentrations of cyclohexylamine in the plasma and testes of rats showed a nonlinear relationship to dietary intake. Elevated concentrations were found at intake greater than 200 mg/kg/day.
Generally, cyclohexylamine, is readily absorbed & rapidly excreted from the body. After admin to rats, cyclohexylamine appears in body tissues with the highest concn in the lungs, spleen, liver, adrenals, heart, GI tract & kidneys.

After oral admin (0.2 g/kg) to rabbits, cyclohexylamine gave rise to unchanged cyclohexylamine & N-hydroxycyclohexylamine in the urine. When C14-labeled cyclohexylamine was admin, 68% of the radioactivity was recovered in the urine after 60 hr. A small amount (0.5%) was eliminated in the breath & 45% of the admin dose was shown to be excreted in the urine as unconjugated cyclohexylamine, 0.2% as N-hydroxycyclohexylamine in conjugated form, & 2.5% as cyclohexanone oxime. The authors postulated the latter metabolite to be an artifact formed form the glucuronide of N-hydroxycyclohexylamine during the hydrolysis procedure.
The metabolites identified indicated that in rats, the metabolism of cyclohexylamine was mainly through hydroxylation of the cyclohexane ring, in man by deamination & in guinea pigs & rabbits by ring hydroxylation & deamination. The metabolites to cyclohexylamine were excreted in both free & conjugated forms.
Most of the cyclohexylamine given by gavage or intraperitoneal injection to rats and guinea pigs was excreted unchanged, and only 4-5% was metabolized within 24 hours. In rabbits, 30% was metabolized. Cyclohexylamine has been reported to be metabolized further to cyclohexanone and then to cyclohexanol in guinea pigs, rabbits and rats. A number of hydroxylated products of cyclohexylamine have been reported in these species, which were excreted in part as glucuronides.

Orally administration cyclamate appears to be readily absorbed by rabbits but less readily by guinea pigs, rats and humans. All of these species convert cyclamate to cyclohexylamine, via the action of gastrointestinal microflora on unabsorbed cyclamate. The metabolism of cyclohexylamine to other products differs somewhat in humans and other species, although most cyclohexylamine is rapidly excreted unchanged in the urine. In rats, it is metabolized mainly by hydroxylation of the cyclohexane ring; in humans, it is metabolized by deamination; and in guinea pigs and rabbits, it is metabolized by ring hydroxylation and deamination.
Mice were fed cyclohexylamine (as the hydrochloride) at a constant intake of 400 mg/kg/day for 13 weeks. Food intake and body weight gain were not affected. The metabolism of (14)C labeled cyclohexylamine administered as a single oral dose (2 uCi per mouse) was not significantly different among animals chronically fed cyclohexylamine for 0, 3, 7, or 13 weeks. The major metabolite produced was 3-aminocyclohexanol; total metabolism was less than 2%. ... Concentrations of cyclohexylamine in plasma (ug/ml) after 3 weeks feeding were 0.20; after 7 weeks 0.18; and after 13 weeks, 4.51 + or - 2.94. Concentrations of the chemical in testes (ug/g wet weight) varied from 6.81 + or - 5.21 at 3 weeks to 4.51 + or - 2.94 at 13 weeks.

Wistar and DA rats were fed cyclohexylamine (as the hydrochloride) at constant intake of 400 mg/kg/day for 13 weeks. The metabolism of (14)C-labeled cyclohexylamine administered as a single oral dose (8 uCi per rat) was similar for both strains of rat, with no consistent effect due to age or prolonged feeding with cyclohexylamine. However, there was reduced elimination of (14)C in the treated Wistar and DA rats compared to that in the controls during the first 6 hr after dosing; the difference was statistically significant at 3 weeks in both strains and at 13 weeks in the DA strain. The major metabolites produced were 3- and 4-aminocyclohexanols; at 13 weeks the total metabolism was 17% to 18% for the Wistar rats, 4% to 6% in the DA rats. After 13 weeks, testicular atrophy was demonstrated in both strains of rat fed cyclohexylamine; DA rats appeared more sensitive to testicular toxicity than the Wistar rats. Concentrations of cyclohexylamine and its metabolites in plasma and in testicular tissue were higher in Wistar rats than in DA rats.
Cyclohexylamine can be formed to a variable extent by microbial biotransformation of cyclamate in the gastrointestinal tract of all species studied; after absorption, it is further metabolized to several compounds that are excreted in the urine.

Cyclohexylamine showed dose dependent kinetics after administration of single oral doses of 35, 200 or 500 mg/kg in mice, with a reduction in plasma clearance from 61 to 53 ml/min/kg, an increase in apparent half-life from 1.4 to 3.5 hr, and an increased area under the testicular concentration vs time curve. During chronic dietary administration the concentrations of cyclohexylamine in the plasma and testes showed little diurna variation. The steady state plasma clearance was 65 ml/min/kg. The concentrations of cyclohexylamine in the plasma and testes of the mice showed a linear relationship to dietary intake, even at the highest intake, about 900 mg/kg/day.
Prepared by catalytic hydrogenation of aniline at elevated temp and pressures. Fractionation of crude reaction product yields cyclohexylamine, unchanged aniline, and high-boiling residue containing n-phenylcyclohexylamine (cyclohexylaniline) and dicyclohexylamine.

CHEMICAL PROFILE: Cyclohexylamine. Boiler water treatment, 70%; rubber chemicals, 17%; chain terminator, 6%; miscellaneous, including oilfield corrosion inhibitors, photographic chemicals, catalysts, intermediates and metal extraction, 7%.
Cyclohexylamine. Boiler water treatment, 60%; rubber chemicals, 12%; nylon chain terminator, 10%; agricultural chemicals, 10%; miscellaneous (including oilfield corrosion inhibitors, photographic chemicals, catalysts, intermediates, metal extraction and exports), 8%.
Cyclohexylamine. Demand: 1986: 9.2 million lb; 1987: 9.4 million lb; 991 /projected/: 10.4 million lb.
AOAC Method 971.17. Cyclohexylamine in Cyclamates and Artificially Sweetened Products by Infrared Spectrophotometric Method.
ASTM Method D4983. Standard Test Method for Cyclohexylamine, Morpholine, and Diethylaminoethanol in Water and Condensed Steam by Direct Aqueous Injection Gas Chromatography.

Warning: Cyclohexylamine is an alkaline-corrosive agent. Contact with eyes may result in severe damage to the cornea, conjunctiva, and blood vessels. Caution is advised. Signs and Symptoms of Cyclohexylamine Exposure: Acute exposure to cyclohexylamine may result in irritation and burning of the skin, eyes, and mucous membranes. Light-headedness, drowsiness, slurred speech, pupillary dilation, increased salivation, dysphagia (difficulty swallowing), abdominal pain, and spontaneous vomiting may occur. Stridor (high-pitched, noisy respirations), dyspnea (shortness of breath), and pulmonary edema are also common. Apathy and mental confusion may develop, with progression to coma and death. Emergency Life-Support Procedures: Acute exposure to cyclohexylamine exposure may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination. Inhalation Exposure: 1. Move victims to fresh air. Emergency personnel should avoid self-exposure to cyclohexylamine. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support. 3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 4. Transport to a health care facility. Dermal/Eye Exposure: 1. Remove victims from exposure. Emergency personnel should avoid self-exposure to cyclohexylamine. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support. 3. Remove contaminated clothing as soon as possible. 4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 30 minutes. 5. Wash exposed skin areas for at least 15 minutes with water. 6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 7. Transport to a health care facility. Ingestion Exposure: 1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support. 2. DO NOT induce vomiting or attempt to neutralize! 3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 4. Activated charcoal is of no value. 5. Give the victims water or milk: children up to 1 year old, 125 mL (4 oz or 1/2 cup); children 1 to 12 years old, 200 mL (6 oz or 3/4 cup); adults, 250 mL (8 oz or 1 cup). Water or milk should be given only if victims are conscious and alert. 6. Transport to a health care facility.

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Cyclohexylamine is produced, as an intermediate or a final product, by process units covered under this subpart.
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. Cyclohexylamine 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.

Cyclohexylamine (CAS # 108-91-8) was evaluated for acute dermal toxicity in solitary male and female New Zealand albino rabbits alternately administered single undiluted dermal applications of 398, 631, 1000, and 1580 mg/kg bodyweight for 24 hours. Clinical signs were observed at all dose levels and included reduced appetite and activity, increasing weakness and collapse. The 1000 mg/kg male and the 1580 mg/kg female both died within 16 hours of treatment, while solitary male and female rabbits of the 398 and 631 mg/kg doses, respectively, saw resolution of all pharmacotoxic signs within 5-7 days. Upon necropsy, the high dose study lethalities were found with lung and liver hyperemia, dark spleen and kidneys, and enlarged gall bladder, while the viscera of the male and female surviving 14-day post-treatment observation appeared normal.
Cyclohexylamine (CAS # 108-91-8) was evaluated for acute oral toxicity in groups of 10 female Swiss-Webster mice administered single peroral doses of 5.0, 6.0, 6.5, 7.5, and 10.0 cc/kg bodyweight (1:10 in 0.5% methylcellulose). Study mortality was comprised of 1/10, 2/10, 4/10, 6/10, and 8/10 of successive incremental dosage groups, respectively, consistent with a LD50 of 730 mg/kg (95% C.L. = 640-830). Death occurred from 1/4 to 2 hours after treatment. Clinical signs of a systemic toxicity included hypokinesis, dyspnea, hyperpnea, diarrhea, diuresis, ptosis, piloerection, salivation, lacrimation, occult blood in urine and feces, cyanosis, somnolence, cachexia, weight loss, and hyperkinesis, random biting and chewing, ataxia, jerking, tremors, opisthotonos, irritability, limb abduction, paralysis, tail erection, hypothermia, clonic convulsions, tonic convulsions, increased and/or decreased muscle tone. Treatment was also associated with vocalization, tissue irritation to necrosis, writhing, self-decimation, and quiet death.

Cyclohexylamine was evaluated for acute oral toxicity in groups of 10 female Swiss-Webster mice administered single peroral cyclohexylamine.HCl (10% solution in 0.5% methylcellulose) at doses of 400, 500, 600, 750, 850, 1250, and 1500 mg/kg. Treatment was associated with mortality in 0/10, 3/10, 6/10, 8/10, 9/10, 9/10, and 10/10 of successive incremental dosage groups, respectively, consistent with a LD50 of 530 mg/kg (95% C.L. 441-637). At doses of 400 mg/kg, mice exhibited clinical signs of toxicity including increased activity, increased respiration, tail erection, salivation, irritability, jerking, clonic convulsions, and death at 1-18 hours following treatment.
Cyclohexylamine was evaluated for dermal irritation in 6 male rabbits each exposed with 0.5 ml on 2 abraded and 2 intact dermal application sites. All intact and abraded sites were charred black such that investigators characterized cyclohexylamine as extremely irritating and destructive on dermal exposure.

Cyclohexylamine's production and use as a corrosion inhibitor in boiling water treatment facilities and chemical intermediate in the manufacture of insecticides, plasticizers, emulsifying agents, dry-cleaning soaps and acid gas absorbents may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 10.1 mm Hg at 25 °C indicates cyclohexylamine will exist solely as a vapor in the ambient atmosphere. Vapor-phase cyclohexylamine as a free base will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 7 hours. If released to soil, cyclohexylamine is expected to have high mobility based upon an estimated Koc of 150. The pKa of cyclohexylamine is 10.6, indicating that this compound will exist in the protonated form in the environment and cations generally adsorb more strongly to soils than their neutral counterparts. Volatilization from moist soil surfaces will not be an important fate process because the cation is not expected to volatilize. Cyclohexylamine may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation is expected to occur in soils based on standard biodegradation studies. A 100% theoretical BOD was observed for 10 mg/l of cyclohexylamine using an acclimated sewage inoculum, plant sludge and river mud over a 14 day incubation period. If released into water, cyclohexylamine is expected to exist primarily as a cation and will adsorb to suspended solids in the water column. Volatilization from water surfaces is not expected to be an important fate process since this compound is expected to exist in the protonated form in water surfaces. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure may occur through inhalation and dermal contact with this compound at workplaces where cyclohexylamine is produced or used. The general population may be exposed to cyclohexylamine primarily through respiratory routes especially at buildings where cyclohexylamine is used as a corrosion inhibitor in steam boiler systems.

Cyclohexylamine is not known to occur as a natural product(1).
Cyclohexylamine's production and use as a corrosion inhibitor in boiling water treatment facilities and chemical intermediate in the manufacture of insecticides, plasticizers, emulsifying agents, dry-cleaning soaps and acid gas absorbents will result in its release to the environment through a variety of waste streams(1,SRC).
TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 150(SRC), determined from a measured log Kow of 1.49(2) and a regression-derived equation(3), indicates that cyclohexylamine as the free base is expected to have high mobility in soil(SRC). A pKa value of 10.6(4) indicates that the protonated form of cyclohexylamine will be the dominant species in moist soil surfaces and cations generally adsorb more strongly to soils than their neutral counterparts. Volatilization of cyclohexylamine from moist soil surfaces is not an important fate process since the cation will not volatilize. The potential for volatilization of cyclohexylamine from dry soil surfaces may exist(SRC) based upon a vapor pressure of 10.1 mm Hg(5). Biodegradation is expected to occur in soils based on standard biodegradability tests conducted with activated sludge and sewage inocula(6-8).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 150(SRC), determined from a measured log Kow of 1.49(2) and a regression-derived equation(3), indicates that cyclohexylamine as the free base is not expected to adsorb to suspended solids and sediment(SRC). A pKa value of 10.6(4) indicates that the protonated form of cyclohexylamine will be the predominant species in water and cations generally adsorb more strongly than their neutral counterparts. Volatilization from water surfaces is not an important fate process(SRC) since the protonated form will not volatilize. According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow of 1.49(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low. Biodegradation is expected to occur in aquatic environments based on standard biodegradability tests conducted with activated sludge and sewage inocula(7-9).
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), cyclohexylamine, which has a vapor pressure of 10.1 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase cyclohexylamine 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 7 hours(SRC), calculated from its rate constant of 5.5X10-11 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3).

A 100% theoretical BOD was observed for 10 mg/l of cyclohexylamine in an acclimated sewage inoculum, plant sludge and river mud over a 14 day incubation period(1). The theoretical BOD of cyclohexylamine (50 mg/l) was 79%, 68 % and 0% in an acclimated sewage inoculum, plant sludge and river mud respectively over a 14 day incubation period(1). The theoretical BOD of cyclohexylamine (100 mg/l) was 79%, 0% and 0% in an acclimated sewage inoculum, plant sludge and river mud respectively over a 14 day incubation period(1). A 200 mg/l sample of cyclohexylamine could not be biodegraded by an activated sludge and was assumed to be toxic to the microflora(2). A theoretical oxygen demand between 25 and 45% was observed for cyclohexylamine in a Warburg apparatus during a 5 day incubation period(3).
The rate constant for the vapor-phase reaction of cyclohexylamine with photochemically-produced hydroxyl radicals has been estimated as 5.5X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Cyclohexylamine will exist predominantly in the protonated form in the environment based on a pKa of 10.6(2). Cyclohexylamine is not expected to directly photolyze due to the lack of absorption in the environmental UV spectrum(SRC).
An estimated BCF of 3 was calculated for cyclohexylamine(SRC), using a log Kow of 1.49(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of cyclohexylamine is estimated as 150(SRC), using a measured log Kow of 1.49(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that cyclohexylamine is expected to have very high mobility in soil. The pKa of cyclohexylamine is 10.6(4), indicating that the protonated form will be the predominant species in moist soils and cations are expected to adsorb strongly to soil surfaces.
With a pKa of 10.6(1), cyclohexylamine will exist predominantly in protonated form in the environment and the protonated form of cyclohexylamine is not expected to volatilize from water or moist soil surfaces(2). The potential for volatilization of cyclohexylamine from dry soil surfaces may exist(SRC) based upon a vapor pressure of 10.1 mm Hg(3).
Cyclohexylamine was detected, not quantified, in the leachate of 2 low-level radioactive disposal facilities located in Maxey Flats, Kentucky and West Valley, New York(1). Effluent from a tire manufacturing plant contained cyclohexylamine at approximately 0.01 ppm(2).
The average concentration of cyclohexylamine was measured as 0.7 ppb in the indoor air of a building in Columbus Ohio where cyclohexylamine is used as a corrosion inhibitor in the boiler system of the building(1).
NIOSH (NOES Survey 1981-1983) has statistically estimated that 64,346 workers (2,914 of these are female) are potentially exposed to cyclohexylamine in the US(1). Occupational exposure may be through inhalation and dermal contact with this compound at workplaces where cyclohexylamine is produced or used(SRC). The general population may be exposed to cyclohexylamine primarily through respiratory routes especially at buildings where cyclohexylamine is used as a corrosion inhibitor in steam boiler systems(2).

About Cyclohexylamine
Helpful information
Cyclohexylamine has not been registered under the REACH Regulation, therefore as yet ECHA has not received any data about Cyclohexylamine from registration dossiers.
Cyclohexylamine is used by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.

Consumer Uses
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the routes by which Cyclohexylamine is most likely to be released to the environment.
Article service life
ECHA has no public registered data on the routes by which Cyclohexylamine is most likely to be released to the environment. ECHA has no public registered data indicating whether or into which articles the substance might have been processed.

Widespread uses by professional workers
Cyclohexylamine is used in the following products: water treatment chemicals, pH regulators and water treatment products, laboratory chemicals and metal working fluids. Cyclohexylamine is used in the following areas: municipal supply (e.g. electricity, steam, gas, water) and sewage treatment and offshore mining. Release to the environment of Cyclohexylamine can occur from industrial use: as an intermediate step in further manufacturing of another substance (use of intermediates) and as processing aid. Other release to the environment of Cyclohexylamine is likely to occur from: indoor use as processing aid, outdoor use as processing aid and indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters).

Formulation or re-packing
Cyclohexylamine is used in the following products: pH regulators and water treatment products and water treatment chemicals.
Release to the environment of Cyclohexylamine can occur from industrial use: formulation of mixtures.
Uses at industrial sites
Cyclohexylamine is used in the following products: water treatment chemicals, pH regulators and water treatment products, laboratory chemicals and metal working fluids.
Cyclohexylamine has an industrial use resulting in manufacture of another substance (use of intermediates).
Cyclohexylamine is used in the following areas: municipal supply (e.g. electricity, steam, gas, water) and sewage treatment, offshore mining and formulation of mixtures and/or re-packaging.
Cyclohexylamine is used for the manufacture of: chemicals.
Release to the environment of Cyclohexylamine can occur from industrial use: in processing aids at industrial sites, as an intermediate step in further manufacturing of another substance (use of intermediates), of substances in closed systems with minimal release and as processing aid.

Cyclohexylamine appears as a clear colorless to yellow liquid with an odor of ammonia. Flash point 90°F. Irritates the eyes and respiratory system. Skin contact may cause burns. Less dense than water. Vapors heavier than air. Toxic oxides of nitrogen produced during combustion.
Cyclohexylamine is a primary aliphatic amine consisting of cyclohexane carrying an amino substituent. It has a role as a human xenobiotic metabolite and a mouse metabolite. It is a conjugate base of a cyclohexylammonium.
Generally, cyclohexylamine, is readily absorbed & rapidly excreted from the body. After admin to rats, cyclohexylamine appears in body tissues with the highest concn in the lungs, spleen, liver, adrenals, heart, GI tract & kidneys.

Orally administration cyclamate appears to be readily absorbed by rabbits but less readily by guinea pigs, rats and humans. All of these species convert cyclamate to cyclohexylamine, via the action of gastrointestinal microflora on unabsorbed cyclamate. The metabolism of cyclohexylamine to other products differs somewhat in humans and other species, although most cyclohexylamine is rapidly excreted unchanged in the urine. In rats, it is metabolized mainly by hydroxylation of the cyclohexane ring; in humans, it is metabolized by deamination; and in guinea pigs and rabbits, it is metabolized by ring hydroxylation and deamination.
Wistar and DA rats were fed cyclohexylamine (as the hydrochloride) at constant intake of 400 mg/kg/day for 13 weeks. The metabolism of (14)C-labeled cyclohexylamine administered as a single oral dose (8 uCi per rat) was similar for both strains of rat, with no consistent effect due to age or prolonged feeding with cyclohexylamine. However, there was reduced elimination of (14)C in the treated Wistar and DA rats compared to that in the controls during the first 6 hr after dosing; the difference was statistically significant at 3 weeks in both strains and at 13 weeks in the DA strain. The major metabolites produced were 3- and 4-aminocyclohexanols; at 13 weeks the total metabolism was 17% to 18% for the Wistar rats, 4% to 6% in the DA rats. After 13 weeks, testicular atrophy was demonstrated in both strains of rat fed cyclohexylamine; DA rats appeared more sensitive to testicular toxicity than the Wistar rats. Concentrations of cyclohexylamine and its metabolites in plasma and in testicular tissue were higher in Wistar rats than in DA rats.

Cyclohexylamine can be formed to a variable extent by microbial biotransformation of cyclamate in the gastrointestinal tract of all species studied; after absorption, it is further metabolized to several compounds that are excreted in the urine.
Cyclohexylamine showed dose dependent kinetics after administration of single oral doses of 35, 200 or 500 mg/kg in mice, with a reduction in plasma clearance from 61 to 53 ml/min/kg, an increase in apparent half-life from 1.4 to 3.5 hr, and an increased area under the testicular concentration vs time curve. During chronic dietary administration the concentrations of cyclohexylamine in the plasma and testes showed little diurna variation. The steady state plasma clearance was 65 ml/min/kg. The concentrations of cyclohexylamine in the plasma and testes of the mice showed a linear relationship to dietary intake, even at the highest intake, about 900 mg/kg/day.
Prepared by catalytic hydrogenation of aniline at elevated temp and pressures. Fractionation of crude reaction product yields cyclohexylamine, unchanged aniline, and high-boiling residue containing n-phenylcyclohexylamine (cyclohexylaniline) and dicyclohexylamine.

Cyclohexylamine is an alkaline-corrosive agent. Contact with eyes may result in severe damage to the cornea, conjunctiva, and blood vessels. Caution is advised. Signs and Symptoms of Cyclohexylamine Exposure: Acute exposure to cyclohexylamine may result in irritation and burning of the skin, eyes, and mucous membranes. Light-headedness, drowsiness, slurred speech, pupillary dilation, increased salivation, dysphagia (difficulty swallowing), abdominal pain, and spontaneous vomiting may occur. Stridor (high-pitched, noisy respirations), dyspnea (shortness of breath), and pulmonary edema are also common. Apathy and mental confusion may develop, with progression to coma and death. Emergency Life-Support Procedures: Acute exposure to cyclohexylamine exposure may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination. Inhalation Exposure: 1. Move victims to fresh air. Emergency personnel should avoid self-exposure to cyclohexylamine. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support. 3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 4. Transport to a health care facility. Dermal/Eye Exposure: 1. Remove victims from exposure. Emergency personnel should avoid self-exposure to cyclohexylamine. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR.

Cyclohexylamine (CAS # 108-91-8) was evaluated for acute inhalation toxicity in 6 male Sprague-Dawley albino rats exposed in a 35 L inhalation chamber to an atmospheric concentration of 13.7 mg/L for 6 hours. During the exposure, rats exhibited nasal and ocular discharge, labored breathing, roughened fur and lethargy. Reduced appetite and activity lasted for one day after treatment. Post-treatment responses were primarily marked by ocular signs of toxicity including near blindness due to corneal cloudiness for 2-6 days. Two of 6 rats had complete loss of sight with corneal blistering upon the final 14th day observation, while all other (4/6) rats were cleared of any clinical signs of toxicity. Upon terminal necropsy on Day 14, all viscera appeared normal.
Cyclohexylamine (CAS # 108-91-8) was evaluated for dermal irritation in 6 male rabbits each exposed with 0.5 ml on 2 abraded and 2 intact dermal application sites. All intact and abraded sites were charred black such that investigators characterized cyclohexylamine as extremely irritating and destructive on dermal exposure.

The rate constant for the vapor-phase reaction of cyclohexylamine with photochemically-produced hydroxyl radicals has been estimated as 5.5X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Cyclohexylamine will exist predominantly in the protonated form in the environment based on a pKa of 10.6(2). Cyclohexylamine is not expected to directly photolyze due to the lack of absorption in the environmental UV spectrum(SRC).
The Koc of cyclohexylamine is estimated as 150(SRC), using a measured log Kow of 1.49(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that cyclohexylamine is expected to have very high mobility in soil. The pKa of cyclohexylamine is 10.6(4), indicating that the protonated form will be the predominant species in moist soils and cations are expected to adsorb strongly to soil surfaces.
With a pKa of 10.6(1), cyclohexylamine will exist predominantly in protonated form in the environment and the protonated form of cyclohexylamine is not expected to volatilize from water or moist soil surfaces(2). The potential for volatilization of cyclohexylamine from dry soil surfaces may exist(SRC) based upon a vapor pressure of 10.1 mm Hg(3).
Cyclohexylamine was detected, not quantified, in the leachate of 2 low-level radioactive disposal facilities located in Maxey Flats, Kentucky and West Valley, New York(1). Effluent from a tire manufacturing plant contained cyclohexylamine at approximately 0.01 ppm(2).The average concentration of cyclohexylamine was measured as 0.7 ppb in the indoor air of a building in Columbus Ohio where cyclohexylamine is used as a corrosion inhibitor in the boiler system of the building(1).
NIOSH (NOES Survey 1981-1983) has statistically estimated that 64,346 workers (2,914 of these are female) are potentially exposed to cyclohexylamine in the US(1). Occupational exposure may be through inhalation and dermal contact with this compound at workplaces where cyclohexylamine is produced or used(SRC). The general population may be exposed to cyclohexylamine primarily through respiratory routes especially at buildings where cyclohexylamine is used as a corrosion inhibitor in steam boiler systems(2).