UREA

B-I-K

CARBAMIDE

CARBAMIDE RESIN

CARBAMIMIDIC ACID

CARBONYL DIAMIDE

CARBONYLDIAMINE

ISOUREA

MOCOVINA (Czech)

PRESPERSION, 75 UREA

PSEUDOUREA

SUPERCEL 3000

UREAPHIL

UREOPHIL

UREVERT

VARIOFORM II

AQUDRATE

57-13-6(Urea)

YR 6250000

Editor's Note: This material is not listed in the Emergency Response Guidebook. Based on the material's physical and chemical properties, toxicity, or chemical group, a guide has been assigned. For additional technical information, contact one of the emergency response telephone numbers listed under Public Safety Measures.

CH4N2O

(NH2)2CO

154-SUBSTANCES - TOXIC and/or CORROSIVE (NON-COMBUSTIBLE)

Uses of urea include fertilizers, plastics, paper, hospital and veterinary use, bakeries, animal feed, resins, barbituric acid production, toothpaste manufacture, mosquito repellent, and as a deicing compound on airport runways (HSDB , 2001).

Urea was formerly used as a diuretic, but has since been replaced by more efficacious agents (HSDB , 2001).

Urea has been used topically in the treatment of ichthyosis and hyperkeratotic skin disorders, and has been used intra-amniotically for the termination of pregnancy (S Sweetman , 2001).

PHARMACEUTICAL -

CHEMICAL GRADES -

PRODUCTS CONTAINING UREA -

NATURAL SOURCES -

NATURAL POLLUTION SOURCES -

Urea is considered a mild to moderate intoxicant and a mild irritant. Exposure causes erythema of eyes and skin. Urea's systemic toxicity is similar to that of mannitol. Massive occupational exposure to carbamide produced persistent respiratory insufficiency.

Adverse effects include nausea, vomiting, dizziness, disorientation, drowsiness, diuresis, hyponatremia, hypokalemia, and confusion. Urea's systemic toxicity is similar to that of mannitol.

TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death.

Contact with molten substance may cause severe burns to skin and eyes.

Avoid any skin contact.

Effects of contact or inhalation may be delayed.

Fire may produce irritating, corrosive and/or toxic gases.

Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Direct eye exposure results in damage only with high urea concentrations or with prolonged exposure (Grant, 1986).

Concentrated urea is a mild skin irritant (RTECS , 1997).

Inhalation of urea fumes caused throat and chest burning in one case. Delayed cough, dyspnea, and exercise-induced bronchoconstriction developed 6 hours after exposure. Nonspecific airway responsiveness measured after 2 months was resolved after 4 months of inhaled steroid therapy (Lemiere et al, 1996).

Large amounts (several grams) of urea would need to be absorbed before most effects would become apparent. No reports of permanent effects or deaths from occupational exposure to urea were found at the time of this review.

Oral or intravenous use of urea in the treatment of glaucoma has rarely caused adverse effects, including rebound glaucoma (Grant, 1986). The effects were considered osmotic rather than direct manifestations of toxicity.

Effects generally resulting from oral or intravenous urea drugs have included headache, nausea, vomiting, disorientation, confusion, fainting, and electrolyte imbalance (HSDB , 1997).

At the time of this review, no studies were found on the effects of chronic exposure to urea in humans.

At the time of this review, no studies were found on the effects of chronic exposure to urea in experimental animals.

Some studies have been done in farm animals receiving urea supplements in the diet with respect to possible hazard from exposure to urea fertilizers. Some poisonings occurred, with liver dysfunction increasing the susceptibility to urea (HSDB , 1997). Urea exposure increased the susceptibility of guinea pigs to become allergic to epoxy resins (HSDB , 1997).

Urea is not highly toxic, and extensive decontamination and treatment is seldom necessary. Gastric decontamination is not indicated in high concentrations due to possible strong irritant effects.

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.

INHALATION EXPOSURE

DERMAL EXPOSURE

EYE EXPOSURE

ORAL EXPOSURE

Information on deaths has come primarily from animal studies. Examples of toxicity are listed below by animal species.

Toxicity and death caused from uremic poisoning are due to a combination of factors, not from urea alone. Urea is one of the less toxic factors seen in uremic poisoning (Giovannetti & Barsotti, 1975).

COWS

GOATS

HORSES

MONKEYS

PIGS

SHEEP

As with all irritants, concentration is not the only factor which affects the extent of tissue damage. The concentrations below should only be used as an estimate, with each patient examined individually.

INHALATION: Concentrations under 50% are not likely to cause tissue damage.

SKIN/MUCOUS MEMBRANES: 25% to 50% concentrations did not produce toxicity in the ear.

INJECTION: Subcutaneous injection of a 6% to 30% solution did not produce toxicity. Injection of a 58% solution in the uterus produced necrosis, 10% injected in the cervix did not.

OCCUPATIONAL EXPOSURE: A 34-year-old previously healthy man developed chronic respiratory insufficiency after falling into a reloading wagon containing granulated carbamide (99.6% carbamide and 0.4% bicarbamide). He was completely covered in the formula for 10 minutes, and arrived at the hospital in a deep coma (Glasgow Coma Scale =4) along with hypotension and a chest X-ray showing signs of acute lung injury. Physical exam demonstrated multiple burns in the mouth and on the vocal cords, epiglottis and mucous membranes. Dermal burns were also present on exposed skin. The patient gradually recovered, but developed a persistent nonproductive cough and dyspnea. CT of the chest showed evidence of allergic alveoli reaction likely of a toxic origin. Spirometry was consistent with obstructive respiratory insufficiency along with a persistent cough and dyspnea with exertion, which were present one year later (Anand & Kabata, 2009).

MIDDLE EAR: Administration of a 25% aerosol and a 50% direct injection did not result in damage (Droegemueller et al, 1978).

UTERINE MYOMETRIUM: Injection of a 58% solution has caused extensive necrosis (Droegemueller et al, 1978).

SUBCUTANEOUS TISSUES (RATS): Injections of a 6% to 30% solution subcutaneously did not produced necrosis within 48 hours (Droegemueller et al, 1978).

CERVIX: Injections of a 10% solution in the human cervix produced brown discolorations. Some studies have shown no evidence of cytotoxicity, while others demonstrated focal necrosis. This was also observed if normal saline was administered (Droegemueller et al, 1978).

ACGIH (American Conference of Governmental Industrial Hygienists, 2010): Not Listed

EPA (U.S. Environmental Protection Agency, 2011): Not Listed

IARC (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004): Not Listed

NIOSH (National Institute for Occupational Safety and Health, 2007): Not Listed

MAK (DFG, 2002): Not Listed

NTP (U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project ): Not Listed

Not Listed

Reference: Lewis, 1992; Knudhansen & Pautong, 1993; RTECS, 2001

Not Listed

Listed as Urea

10 mg/m3

Ceiling or Short-term TWA:

Skin Notation: No

Dermal Sensitizer: No

Candidate WEEL: No

WEEL Under Review: Yes

Not Listed

Not Listed

Not Listed

Not Listed

Not Listed

Not Listed

Editor's Note: The D, F, and K series waste numbers and Appendix VIII to Part 261 -- Hazardous Constituents were not included. Please refer to 40 CFR Part 261.

Not Listed

Not Listed

Not Listed

Listed as: Urea

Not Listed

Not Listed

Not Listed

Store urea away from heat (HSDB , 1993).

Store at ambient temperature (CHRIS , 1993).

Wear positive pressure self-contained breathing apparatus (SCBA).

Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection.

Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.

Specific recommendations and test data for this chemical were not found in the available manufacturers' product literature. A complete list of consulted manufacturers and references is presented below.

Editor's Note: This material is not listed in the Emergency Response Guidebook. Based on the material's physical and chemical properties, toxicity, or chemical group, a guide has been assigned. For additional technical information, contact one of the emergency response telephone numbers listed under Public Safety Measures.

POTENTIAL FIRE OR EXPLOSION HAZARDS - EMERGENCY RESPONSE GUIDEBOOK, GUIDE 154 (ERG, 2004)

Urea is noncombustible (HSDB , 1993; Sax & Lewis, 1987).

Not Listed

Dry chemical, CO2 or water spray.

Dry chemical, CO2, alcohol-resistant foam or water spray.

Move containers from fire area if you can do it without risk.

Dike fire control water for later disposal; do not scatter the material.

Fight fire from maximum distance or use unmanned hose holders or monitor nozzles.

Do not get water inside containers.

Cool containers with flooding quantities of water until well after fire is out.

Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

ALWAYS stay away from tanks engulfed in fire.

Not Listed

When heated to decomposition, urea emits toxic fumes of oxides of nitrogen (Lewis, 1992).

Data presented from the Emergency Response Guidebook Table of Initial Isolation and Protective Action Distances are for use when a spill has occurred and there is no fire. If there is a fire, or if a fire is involved, evacuation information presented under FIRE - PUBLIC SAFETY EVACUATION DISTANCES should be used.

Generally, a small spill is one that involves a single, small package such as a drum containing up to approximately 200 liters, a small cylinder, or a small leak from a large package. A large spill is one that involves a spill from a large package, or multiple spills from many small packages.

Suggested distances to protect from vapors of toxic-by-inhalation and/or water-reactive materials during the first 30 minutes following the spill.

SPILL OR LEAK PRECAUTIONS - EMERGENCY RESPONSE GUIDEBOOK, GUIDE 154 (ERG, 2004)

RECOMMENDED PROTECTIVE CLOTHING - EMERGENCY RESPONSE GUIDEBOOK, GUIDE 154 (ERG, 2004)

At the time of this review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices (HSDB , 1993).

WATER SPILL: Contain by damming, water diversion, or natural barriers. Remove and treat contaminated liquids. Absorb small amounts of liquid spill with natural or synthetic sorbents, shovel into containers and cover (HSDB , 1993).

If urea is spilled in solid form, shovel material into containers and cover. Construct barriers to contain solutions or divert to impermeable holding area. Remove material by manual or mechanical means (HSDB , 1993).

In situ amelioration: Carbon will be most effective. Seek professional environmental engineering assistance (HSDB , 1993).

OTHER

Snails: Studies were performed to evaluate the toxic effects of urea on the eggs, juveniles, and adults of two species of freshwater snails (Helisoma trivolvis and Biomphalaria havanensis). Results of tests indicated 24-hour LC50 values of 14,241 mg/L and 13,532 mg/L for eggs; 18,255 mg/L and 24,504 mg/L for juveniles and 30,060 mg/L and 26,024 mg/L for adults of H. trivolvis and B. havanensis, respectively. Following 48-hour exposure, the concentrations of urea killing 100% of snails were 25,000 mg/L for H. trivolvis and 35,000 mg/L for B. havanensis (Tchounwou et al, 1991).

Claris batrachus: The effect of urea was tested on this fresh water fish. Slight decreases were seen in hemoglobin, red blood cell count, and hemocrit at lower concentrations for short intervals, while for higher concentrations significant decreases during shorter intervals were seen. Total leucocyte count increased during toxicity (Trivedi et al, 1990).

Toxicity threshold: Scenedesmus quadricauda (green algae), Greater than 10,000 mg/L, toxic effect: multiplication inhibition of cell

Toxicity threshold: Entosiphon sulcatum (protozoa), Greater than 29 mg/L, toxic effect: inhibition of cell multiplication

30,000 mg/L/24 hr, creek chub, all died, fresh water

16,000 mg/L/24 hr, creek chub, all survived, fresh water

1.32 (at 18/4 degrees C) (Budavari, 1996)

1.34 (at 20 degrees C) (CHRIS, 2005)

1.335 g/cm(3) (Sax & Lewis, 1987)

1.32 g/cm(3) (Budavari, 1996)

132.7 degrees C (Upon further heating, urea decomposes to biuret, ammonia, and cyanuric acid) (Budavari, 1996)

1,000,000 ppm (at 25 degrees C) (OHM/TADS, 2005)

1 g dissolves in 1 mL water (Budavari, 1996).

1 g dissolves in 10 mL 95% alcohol, 1 mL boiling 95% alcohol, 20 mL absolute alcohol, 6 mL methanol, and 2 mL glycerol (Budavari, 1996).

It is soluble in acetic acid, pyrimidine, and concentrated hydrochloric acid (HSDB, 2005; Budavari, 1996).

Urea is almost insoluble in benzene and chloroform, and is very slightly soluble in ether (HSDB, 2005; Budavari, 1996).

Odorless (CHRIS, 2005)

135 degrees C (HSDB, 2005).

pKa = 0.1 (at 21 degrees C) (Osol & Hoover, 1975)

15.4 kJ/mol (at melting point) (HSDB, 2005)

1.78 mPa-s (46% solution at 20 degrees C); 1.81 mPa-s (at 137 degrees C); 1.90 mPa-s (saturated solution at 20 deg C) (HSDB, 2005)