Common Name: Thiourea CAS Number: 62-56-6 DOT Number: UN 2877 Date: October 30, 1986 ----------------------------------------- HAZARD SUMMARY * Thiourea can affect you when breathed in. * Thiourea is a CARCINOGEN--HANDLE WITH EXTREME CAUTION. * Exposure may damage the bone marrow, causing reduced red blood cells, white blood cells and platelets. * Repeated exposure can cause goiter (enlarged thyroid gland). * A related chemical (Naphthylthiourea) in higher exposures can cause fluid in the lungs, a medical emergency. It is not known if Thiourea has this effect. IDENTIFICATION Thiourea is a colorless, lustrous crystalline (sand-like) material with a bitter taste. It is used in photography, pharmaceutical and pesticide manufacture and in textile chemicals. REASON FOR CITATION * Thiourea is on the Hazardous Substance List because it is cited by DOT, NTP, DEP and CAG. * This chemical is on the Special Health Hazard Substance List because it is a CARCINOGEN and a MUTAGEN. HOW TO DETERMINE IF YOU ARE BEING EXPOSED * Exposure to hazardous substances should be routinely evaluated. This may include collecting personal and area air samples. You can obtain copies of sampling results from your employer. You have a legal right to this information under OSHA 1910.20. * If you think you are experiencing any work-related health problems, see a doctor trained to recognize occupational diseases. Take this Fact Sheet with you. ----------------------------------------- WORKPLACE EXPOSURE LIMITS No occupational exposure limits have been established for Thiourea. This does not mean that this substance is not harmful. Safe work practices should always be followed. * Thiourea is a PROBABLE CARCINOGEN in humans. There may be no safe level of exposure to a carcinogen, so all contact should be reduced to the lowest possible level. WAYS OF REDUCING EXPOSURE * Where possible, enclose operations and use local exhaust ventilation at the site of chemical release. If local exhaust ventilation or enclosure is not used, respirators should be worn. * A regulated, marked area should be established where Thiourea is handled, used, or stored. * Wear protective work clothing. * Wash thoroughly immediately after exposure to Thiourea and at the end of the workshift. * Post hazard and warning information in the work area. In addition, as part of an ongoing education and training effort, communicate all information on the health and safety hazards of Thiourea to potentially exposed workers. This Fact Sheet is a summary source of information of all potential and most severe health hazards that may result from expo-sure. Duration of exposure, concentration of the substance and other factors will affect your susceptibility to any of the potential effects described below. ------------------------------------------ HEALTH HAZARD INFORMATION Acute Health Effects The following acute (short-term) health effects may occur immediately or shortly after exposure to Thiourea: * High exposure to a related chemical (Naphthylthiourea) can cause fluid to build up in the lungs, with severe shortness of breath, a medical emergency. It is not known whether Thiourea has this effect. Chronic Health Effects The following chronic (long-term) health effects can occur at some time after exposure to Thiourea and can last for months or years: Cancer Hazard * Thiourea is a PROBABLE CARCINOGEN in humans. It has been shown to cause thyroid, liver and other cancers in animals. * Many scientists believe there is no safe level of exposure to a carcinogen. Such substances may also have the potential for causing reproductive damage in humans. Reproductive Hazard * According to the information presently available to the New Jersey Department of Health, Thiourea has not been tested for its ability to adversely affect reproduction. Other Long-Term Effects * Exposure can damage the bone marrow causing reduced red blood cells (anemia), white cells (with reduced ability to fight infections) and/or reduced platelets (reduced blood clotting, bruising). * Repeated exposure can cause goiter (an enlarged thyroid gland in the neck) and causes reduced thyroid hormone. * Exposure may cause skin allergy to develop, with rash. If allergy develops, even low future exposures may cause rash. * Very irritating substances may affect the lungs. It is not known whether Thiourea causes lung damage. Medical Testing Before beginning employment and at regular times after that, for those with frequent or potentially high exposures, the following are recommended: * Lung function tests. * Complete blood count. * Consider thyroid test for thyroxin. If symptoms develop or overexposure is suspected, the following may be useful: * Consider chest x-ray after acute over-exposure. * Evaluation by a qualified allergist, including careful exposure history and special testing, may help diagnose skin allergy. Any evaluation should include a careful history of past and present symptoms with an exam. Medical tests that look for damage already done are not a substitute for controlling exposure. Request copies of your medical testing. You have a legal right to this information under OSHA 1910.20. WORKPLACE CONTROLS AND PRACTICES Unless a less toxic chemical can be substituted for a hazardous substance, ENGINEERING CONTROLS are the most effective way of reducing exposure. The best protection is to enclose operations and/or provide local exhaust ventilation at the site of chemical release. Isolating operations can also reduce exposure. Using respirators or protective equipment is less effective than the controls mentioned above, but is sometimes necessary. In evaluating the controls present in your workplace, consider: (1) how hazardous the substance is, (2) how much of the substance is released into the workplace and (3) whether harmful skin or eye contact could occur. Special controls should be in place for highly toxic chemicals or when significant skin, eye, or breathing exposures are possible. In addition, the following control is recommended: * Where possible, automatically transfer Thiourea from drums or other storage containers to process containers. Good WORK PRACTICES can help to reduce hazardous exposures. The following work practices are recommended: * Workers whose clothing has been contaminated by Thiourea should change into clean clothing promptly. * Do not take contaminated work clothes home. Family members could be exposed. * Contaminated work clothes should be laundered by individuals who have been informed of the hazards of exposure to Thiourea. * On skin contact with Thiourea, immediately wash or shower to remove the chemical. At the end of the workshift, wash any areas of the body that may have contacted Thiourea, whether or not known skin contact has occurred. * Do not eat, smoke, or drink where Thiourea is handled, processed, or stored, since the chemical can be swallowed. Wash hands carefully before eating or smoking. * Use a vacuum or a wet method to reduce dust during clean-up. Do not dry sweep. * When vacuuming, a high efficiency particulate absolute (HEPA) filter should be used, not a standard shop vacuum. PERSONAL PROTECTIVE EQUIPMENT WORKPLACE CONTROLS ARE BETTER THAN PERSONAL PROTECTIVE EQUIPMENT. However, for some jobs (such as outside work, confined space entry, jobs done only once in a while, or jobs done while workplace controls are being installed), personal protective equipment may be appropriate. The following recommendations are only guidelines and may not apply to every situation. Clothing * Avoid skin contact with Thiourea. Wear protective gloves and clothing. Safety equipment suppliers/manufacturers can provide recommendations on the most protective glove/clothing material for your operation. * All protective clothing (suits, gloves, footwear, headgear) should be clean, available each day and put on before work. Eye Protection * Eye protection is included in the recommended respiratory protection. Respiratory Protection IMPROPER USE OF RESPIRATORS IS DANGEROUS. Such equipment should only be used if the employer has a written program that takes into account workplace conditions, requirements for worker training, respirator fit testing and medical exams, as described in OSHA 1910.134. * Engineering controls must be effective to ensure that exposure to Thiourea does not occur. * At any exposure level, use a MSHA/NIOSH approved supplied-air respirator with a full facepiece operated in the positive pressure mode or with a full facepiece, hood, or helmet in the continuous flow mode, or use a MSHA/NIOSH approved self- contained breathing apparatus with a full facepiece operated in pressure-demand or other positive pressure mode. Common Name: Thiourea DOT Number: UN 2877 DOT Emergency Guide code: 53 CAS Number: 62-56-6 ---------------------------------------- NJ DOH Hazard rating FLAMMABILITY Not Found REACTIVITY Not Found ---------------------------------------- POISONOUS GASES ARE PRODUCED IN FIRE ---------------------------------------- Hazard Rating Key: 0=minimal; 1=slight; 2=moderate; 3=serious; 4=severe FIRE HAZARDS * Use dry chemical, CO2, water spray, or foam extinguishers. * POISONOUS GASES ARE PRODUCED IN FIRE, including Nitrogen Oxides and Sulfur Oxides. * If employees are expected to fight fires, they must be trained and equipped as stated in OSHA 1910.156. SPILLS AND EMERGENCIES If Thiourea is spilled, take the following steps: * Restrict persons not wearing protective equipment from area of spill until clean-up is complete. * Collect powdered material in the most convenient and safe manner and deposit in sealed containers. * It may be necessary to contain and dispose of Thiourea as a HAZARDOUS WASTE. Contact your Department of Environmental Protection (DEP) or your regional office of the federal Environmental Protection Agency (EPA) for specific recommendations. ========================================== FOR LARGE SPILLS AND FIRES immediately call your fire department. ========================================== HANDLING AND STORAGE * Prior to working with Thiourea you should be trained on its proper handling and storage. * Thiourea must be stored to avoid contact with ACRYLALDEHYDE, Hydrogen Peroxide and Nitric Acid since violent reactions occur. * Store in tightly closed containers in a cool, well ventilated area. FIRST AID Eye Contact * Immediately flush with large amounts of water for at least 15 minutes, occasionally lifting upper and lower lids. Skin Contact * Remove contaminated clothing. Wash contaminated skin with water. Breathing * Remove the person from exposure. * Begin rescue breathing if breathing has stopped and CPR if heart action has stopped. * Transfer promptly to a medical facility. * Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. PHYSICAL DATA Water Solubility: Soluble Other Names and Formulations: 2-Thiourea; Thiocarbamade. ------------------------------------------ Not intended to be copied and sold for commercial purposes. ------------------------------------------ NEW JERSEY DEPARTMENT OF HEALTH Right to Know Program CN 368, Trenton, NJ 08625-0368 ------------------------------------------ ------------------------------------------ ECOLOGICAL INFORMATION Thiourea is a crystalline solid used in photography as a fixing agent and a stain remover on negatives, as a chemical reagent, and as an accelerator in the vulcanization process. It may enter the environment from industrial discharges, photographic laboratories, or spills. ACUTE (SHORT-TERM) ECOLOGICAL EFFECTS Acute toxic effects may include the death of animals, birds, or fish, and death or low growth rate in plants. Acute effects are seen two to four days after animals or plants come in contact with a toxic chemical substance. Thiourea has slight acute toxicity to aquatic life. Thiourea has caused dormancy break increase, and several other effects, in numerous agricultural crops. Insufficient data are available to evaluate or predict the short-term effects of thiourea on birds or land animals. CHRONIC (LONG-TERM) ECOLOGICAL EFFECTS Chronic toxic effects may include shortened lifespan, reproductive problems, lower fertility, and changes in appearance or behavior. Chronic effects can be seen long after first exposure(s) to a toxic chemical. Thiourea has slight chronic toxicity to aquatic life. Insufficient data are available to evaluate or predict the long-term effects of thiourea to plants, birds, or land animals. WATER SOLUBILITY Thiourea is highly soluble in water. Concentrations of 1,000 milligrams and more will mix with a liter of water. DISTRIBUTION AND PERSISTENCE IN THE ENVIRONMENT Thiourea will react rapidly with water and therefore will not accumulate in aquatic organisms or the environment. SUPPORT DOCUMENT: AQUIRE Database, ERL-Duluth, U.S. EPA., Phytotox.