Tetrahydrofuran

Tetrahydrofuran (also known as tetramethylene oxide), has the formula C4H8O. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][1] It is a clear colourless liquid with an ethereal odour. It is less dense than water and its vapours are heavier than air. Tetrahydofuran is highly flammable and oxidises readily in air to form unstable peroxides that may explode spontaneously. [2]

Uses [3]

THF is used as a solvent for polyvinyl chlorides, vinylidene chloride polymers, natural and synthetic resins (particularly vinyls), in topcoating solutions, polymer coatings, cellaphane, protective coatings, adhesives, magnetic strips and printing inks. It is also used for Grignard and metal hydride reactions. THF is used as an intermediate in chemical synthesis. For example, it is used in the preparation of chemicals including adipic acid, butadiene, acrylic acid, butylrolactone, succinic acid, 1,4-butanediol diacetate, motor fuels, vitamins, hormones, pharmaceuticals, synthetic perfumes, organometallic compounds, and insecticides. It is also used in the manufacture of polytetramethylene ether glycol, polyurethane elastomers, and elastic polymers. THF can be used in the fabrication of materials for food packaging, transport, and storage.

Sources & Routes of Exposure

Sources of Exposure [3]

  • Occupational exposure to tetrahydrofuran may occur through inhalation and dermal contact with this compound at workplaces where tetrahydrofuran is produced or used.

Routes of Exposure [4]

Exposure to tetrahydrofuran can occur via:

  • Inhalation;
  • Ingestion;
  • contact with the eyes;
  • contact with the skin

Health Effects [5]

Acute Effects

Exposure to concentrated THF in the workplace has caused dermatitis and exposure to high levels from inhalation has been found to be irritating to the eyes, and nose and throat. The estimated fatal oral dose in an adult human range from 3,500 to 35,000 milligrams (mg). Inhalation of vapours in amounts much greater than usually found in environmental contamination affects the central nervous system (CNS), which can result in headache, dizziness and fatigue. Animal studies confirm the effects seen in humans.

Chronic Effects

There are no epidemiological studies with which to determine the effects of chronic human exposure to THF. However, in case studies of individual workers exposed by inhalation to THF, liver, kidney, CNS and respiratory effects were observed. Both oral and inhalation exposures to high THF levels in animal studies reported liver, lung, and kidney damage. Changes in blood chemistry were also noted in several animal studies.

Carcinogenic Effects

There are no long-term studies of human exposure to determine whether THF is carcinogenic. In a two-year inhalation study, THF exposure resulted in increases in kidney tumours in male rats and liver tumours in female mice. Another animal study for carcinogenicity indicated no tumour causing effects after application of THF to the skin of mice. THF has not been officially evaluated by the US Environmental Protection Agency for its cancer potential. Based on the one study showing kidney and liver tumour increases in rodents, THF would likely be put into the “suggested evidence of cancer potential” classification under the current EPA cancer guidelines.

Teratogenic/Reproductive Effects

In an animal study in which rats were exposed to THF in drinking water, decreased body weights and developmental delays were seen in offspring.

Safety [6,3]

First Aid Measures

  • Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention.
  • Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention.
  • Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention.
  • Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention.
  • Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious or corrosive. Seek medical attention.
  • Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. If large quantities of this material are swallowed, call a physician immediately. Loosen tight clothing such as a collar, tie, belt or waistband.

Exposure Controls & Personal Protection

Personal Protection

The follow personal protective equipment is recommended when handling tetrahydrofuran:

  • Splash goggles;
  • Lab coat;
  • Vapour respirator (Be sure to use an approved/certified respirator or equivalent); and
  • Gloves.

Personal Protection in Case of a Large Spill:

  • Splash goggles;
  • Full suit;
  • Vapour respirator;
  • Boots; and
  • Gloves.
  • A self-contained breathing apparatus should be used to avoid inhalation of the product.
  • Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.

Exposure Controls

  • If tetrahydrofuran contacts the skin, workers should immediately wash the affected areas with soap and water.
  • Clothing contaminated with tetrahydrofuran should be removed immediately, and provisions should be made for the safe removal of the chemical from the clothing.
  • Persons laundering the clothes should be informed of the hazardous properties of tetrahydrofuran, particularly its potential to cause irritation of the eyes, nose, and respiratory tract.
  • A worker who handles tetrahydrofuran should thoroughly wash hands, forearms, and face with soap and water before eating, using tobacco products, or using toilet facilities.
  • Workers should not eat, drink, or use tobacco products in areas where tetrahydrofuran or a solution containing tetrahydrofuran is handled, processed, or stored.

Storage

Tetrahydrofuran (with an inhibitor) should be stored in a cool, dry, well-ventilated area in tightly sealed metal or amber glass containers that are labelled in accordance with OSHA’s Hazard Communication Standard. Storage areas must meet requirements for an OSHA Class IB flammable liquid. Outside or detached storage is preferred; inside storage should be in a standard flammable liquids storage area or room. Containers of tetrahydrofuran should be protected from physical damage and should be stored separately from oxidisers, heat, sparks, and open flame. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arrestors. Only nonsparking tools may be used to handle tetrahydrofuran. To prevent static sparks, containers should be grounded and bonded for transfers. Because containers that formerly contained tetrahydrofuran may still hold product residues, they should be handled appropriately.

Spills & Leaks

In the event of a spill or leak involving tetrahydrofuran, persons not wearing protective equipment and clothing should be restricted from contaminated areas until cleanup has been completed. The following steps should be undertaken following a spill or leak:

  • Do not touch the spilled material;
  • Stop the leak if it is possible to do so without risk;
  • Notify safety personnel;
  • Remove all sources of heat and ignition;
  • Ventilate potentially explosive atmospheres;
  • Water spray may be used to reduce vapours, but the spray may not prevent ignition in closed spaces;
  • Use non-sparking tools for clean-up.

For small liquid spills, take up with sand or other noncombustible absorbent material and place into closed containers for later disposal. For large liquid spills, build dikes far ahead of the spill to contain the tetrahydrofuran for later reclamation or disposal.

Regulation

United States [7]

OSHA: The Occupational Safety & Health Administration has set the following Permissible Exposure Limit (PEL) for tetrahydrofuran:

  • General Industry: 29 CFR 1910.1000 Z-1 Table — 200 ppm, 590 mg/m3 TWA
  • Construction Industry: 29 CFR 1926.55 Appendix A — 200 ppm, 590 mg/m3 TWA
  • Maritime: 29 CFR 1915.1000 Table Z-Shipyards — 200 ppm, 590 mg/m3 TWA

ACGIH: American Conference of Governmental Industrial Hygienists has set a Threshold Limit Value (TLV) for tetrahydrofuran of 200 ppm, 590 mg/m3 TWA; 250 ppm, 737 mg/m3 STEL; BEI

NIOSH: National Institute for Occupational Safety and Health has set a Recommended Exposure Limit (REL)for tetrahydofuran of 200 ppm, 590 mg/m3 TWA; 250 ppm, 735 mg/m3

Australia [8]

Safe Work Australia: Safe Work Australia has established a Time Weighted Average Concentration (TWA) for tetrahydrofuran of 100ppm or 295mg/m3 for a 40-hour workweek.

References

http://www.solventis.net/others/tetrahydrofuran

http://www.chemicalbook.com/ProductChemicalPropertiesCB6852795_EN.htm

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=181714

http://toxnet.nlm.nih.gov/cgi-bin/sis/search2/r?dbs+hsdb:@term+@rn+109-99-9

http://des.nh.gov/organization/commissioner/pip/factsheets/ard/documents/ard-ehp-23.pdf

http://www.sciencelab.com/msds.php?msdsId=9927294

https://www.osha.gov/dts/chemicalsampling/data/CH_271000.html

http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/772/Workplace-exposure-standards-airborne-contaminants.pdf

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