CAS: 110-91-8 DOT: 2054 SIC Codes: 2831, 2879, 2879, 2834, 2834 Synonyms: diethylene imide oxide; diethylene imidoxide; diethylene oximide; diethylenimide oxide; morpholine, aqueous mixture; 1-oxa-4-azacyclohexane; tetrahydro-p-isoxazine; tetrahydro-1,4-isoxazine; tetrahydro-1,4-oxazine; tetrahydro-2H-1,4-oxazine Molecular Formula: C4H9NO Molecular Weight: 87.14 pH: 25% Aqueous solution approximately pH 11 Color and Form: Colorless liquid; mobile liquid Odor: Characteristic amine; penetrating Odor Threshold: Air: 0.01 ppm (v/v) Density: 1.0007 at 20°C Surface Tension: 37.5 dynes/cm at 20°C Viscosity: 2.23 cPs at 20°C Boiling Point: 128.9°C at 760 mm Hg Melting Point: -4.9°C Autoignition Temperature: 590°F (310°C) [R5, p. 305M-147] Flammability Limits: Lower 2.0%, upper 11.2% [R5, p. 305M-147] Firefighting Procedures: Alcohol foam, carbon dioxide, dry chemical [R4]. Solubility: Soluble in, organic solvents; immiscible with concentration sodium hydroxide solution; miscible with acetone, benzene, ether, castor oil, methanol, ethanol, ethylene glycol, 2-hexanone, linseed oil, turpentine, pine oil; miscible with water with evolution of some heat Vapor Pressure: 6 mm Hg at 20°C Stability and Shelf Life: Volatile [R6, 2] Other Chemical/Physical Properties: Dipole moment: 1.58; pkb 5.6; strong base; dissolves 109% dimethylamine; more than 5% naphtha; 34% trimethylamine; 33% methylamine; dissolves less than 1% paraffin oil, 5% sulfur does not form an azeotrope with water, hygroscopic Protective Equipment: Workers should be supplied with hand and eye protective equipment [R1]. Disposal Method: (1) Pour onto thick layer of sand-soda ash mixture (90/10). Mix in paper box and burn in incinerator with scrap wood or paper. Stay upwind (2) Dissolve in flammable solvent and burn in incinerator with afterburner and scrubber. Can be made immiscible by adding large amount of NaOH. Common Uses: Solvent for resins, waxes, casein, dyes [R3]; defoaming agent in manufacture of paper, and paperboard; constituent of certain adhesives; as neutralizing and scrubbing agent [R1]; as surface-active agents and emulsifiers (fatty acid salts) [R3]; as corrosion inhibitors, antioxidants, plasticizers, viscosity improvers, insecticides; as fungicides, herbicides, local anesthetics, and antiseptics (morpholine compound) [R3]; chemical intermediate for disulfide and sulfenamide rubber accelerators, n, n-dithiomorpholine heat stabilizer, dimorpholine polysulfide corrosion inhibitor, di-4-morpholinyl monosulfide antioxidant, morpholine oleate, a wax component, pharmaceuticals, softening, and whitening agents, N-hexadecylmorpholine, an intermediate for bactericides, photographic developer, salts of sulfonated azo dyes, morpholine p-toluenesulfonic acid salt; solvent for extractions [R2] Standard Codes: NFPA–2,3,0; ICC–no; USCG–grade D combustible liquid. Persistence: Biodegrades at moderate rate. Inhalation Limit: 20 mg/m3
Direct Contact: Eyes, skin, mucous membranes. General Sensation: Amino odor. Odor detectable at 0.01- 0.14 ppm in air. Vapor pressure 66 times odor threshold; strong caustic; skin irritation grade 6–necrosis undiluted; may cause liver and kidney damage. eye irritation grade 7–severe burns 0.5 ml; can be absorbed through skin at toxic levels. TLV 20 ppm. Personal Safety: Wear full protective clothing and self-contained breathing apparatus. neoprene and unsupported PVA not recommended for gloves; equipment should have no copper or copper alloy parts. Acute Hazard Level: Irritant. Moderately toxic with exposure by all routes. Will produce BOD. Emits toxic vapors when heated to decomposition. Chronic Hazard Levels: Unknown Degree of Hazard to Public Health: Irritant. Moderately toxic by all routes. Emits toxic vapors when heated to decomposition. Action Level: Notify fire, and air authority. Enter from upwind and remove ignition source. Restrict access. to affected waters. On Site Restoration: Can be neutralized with acetic acid. Treat with carbon before neutralization. seek professional environmental engineering assistance through EPA s Environmental Response Team (ERT), Edison, NJ, 24-hour no., 908-548-8730. Beach or Shore Restoration: Wash with dilute acid. Availability of Countermeasure Material: Carbon–water treatment plants, sugar refineries. Industrial Fouling Potential: Volatility suggests rupture hazard when confined in boiler feed or cooling system waters. Disposal Notification: Contact local air authority. Major Water Use Threatened: Recreation, potable supply, fisheries, industrial Probable Location and State: Colorless oily liquid. Will dissolve. Water Chemistry: Forms alkaline solution. Subject to biodegradation. Occupational Recomendations: Threshold-limit-time weighted average (TWA) 20 ppm, 71 mg/m3 , skin (1991) [R10, 28] Biological Half-Life: After ip admin of 125 mg/kg 14 C-morpholine (50 micro-Ci) /animal, the blood plasma half-lives in the rat, hamster, and guinea pig were 115, 120, and 300-min, respectively [R7]. Biodegradation: Morpholine was completely degraded microbiologically and 2 organisms isolated, each capable of growth in a simple mineral salts medium with morpholine as the sole source of C, N, and energy. Excess N is liberated as ammonia. The enzymes responsible for the oxidation of morpholine are inducible. The possible effects of other chemicals in trade wastes containing morpholine on nitrification and morpholine oxidation are described [R8]. Bioconcentration: Because morpholine is miscible with water (1) and has a measured octanol/water partition coefficient (Kow ) of 0.14 (2), its tendency to bioconcentrate will be extremely low (SRC) [R9]. General Response: Stop discharge if possible. Avoid contact with liquid and vapor. Call fire department. Isolate and remove discharged material. Notify local health and pollution control agencies. Fire Response: Flammable flashback along vapor trail may occur. Vapor may explode if ignited in an enclosed area. Extinguish with water, dry chemical, or carbon dioxide. Cool exposed containers with water. Exposure Response: Call for medical aid. VAPOR irritating to eyes, nose, and throat. If inhaled, will cause nausea, headache, or difficult breathing. Move to fresh air. If breathing has stopped, give artificial respiration. If breathing is difficult, give oxygen. LIQUID irritating to skin, and eyes. Remove contaminated clothing and shoes. Flush affected areas with plenty of water. IF IN EYES, hold eyelids open, and flush with plenty of water. IF SWALLOWED and victim is CONSCIOUS, have victim drink water, or milk, and have victim induce vomiting. IF SWALLOWED and victim is UNCONSCIOUS OR HAVING CONVULSIONS, do nothing except keep victim warm. Response to Discharge: Disperse and flush. Water Response: Effect of low concentrations on aquatic life is unknown. May be dangerous if it enters water intakes. Notify local health and wildlife officials. Notify operators of nearby water intakes. Exposure Symptoms: Liquid causes skin and eye burns. Breathing vapors or absorption through skin may cause nausea and headache. Exposure Treatment: INHALATION: If ill effects occur, move patient to fresh air, keep him quiet, and warm, and call a physician; if breathing stops, start artificial respiration. INGESTION: Force milk, or water, then immediately induce vomiting; treat symptomatically; no known antidote. SKIN OR EYES: immediately flush with plenty of water for at least 15-min; for eyes get medical attention promptly. References: 1. International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I and II. Geneva, Switzerland: International Labour Office, 1983. 1406
4. Sax, N. I. Dangerous Properties of Industrial Materials,. 5th ed. New York: Van Nostrand Reinhold, 1979. 841
5. National Fire Protection Association. Fire Protection Guide on Hazardous Materials . 7th ed. Boston, MA: National Fire Protection Association, 1978.
6. Clayton, G.D., and F.E. Clayton (eds.). Pattys Industrial Hygiene and Toxicology : Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley and Sons, 1981-1982.
7. Sohn, O.S., et al., Metabolism, and disposition of morpholine in the rat, hamster, and guinea pig; Toxicol Appl Pharmacol64 (3): 486-91 (1982)
9. (1) Merck Index; an Encyclopedia of Chemicals, Drugs, and Biologicals10th ed. p. 899 (1983) (2) Hansch, C., and A. J. Leo. Medchem ProjectIssue No. 26 Claremont CA Pomona College (1985)
10. American Conference of Governmental Industrial Hygienists. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices for 1992-1993 . Cincinnati, OH: ACGIH, 1992.
