Ethyl formate

Ethyl formate is an ester formed when ethanol (an alcohol) reacts with formic acid (a carboxylic acid)[1]. It has the characteristic smell of rum and is partially responsible for the flavor of raspberries, occurring naturally in some plant oils, fruits, and juices[1]. Ethyl formate does not occur naturally in the animal kingdom.

Exposure

Ethyl formate is generally recognized as safe by the U.S. Food and Drug Administration. However, according to the U.S Occupational Safety and Health Administration (OSHA), ethyl formate can irritate eyes, skin, mucous membranes, and the respiratory system of humans and other animals; it is also a central nervous system depressant. In industry, it is used as a solvent for cellulose nitrate, cellulose acetate, oils, and greases. It can be used as a substitute for acetone; workers may also be exposed to it under the following circumstances:

• during spray, brush, or dip applications of lacquers
• during the manufacture of safety glass
• when fumigating tobacco, cereals, and dried fruits (as an alternative to methyl bromide under the U.S. Department of Agriculture quarantine system)

OSHA considers a time-weighted average of 100 parts per million (300 milligrams per cubic meter) over an eight-hour period as the permissible exposure limit. The U.S. National Institute for Occupational Safety and Health (NIOSH) also considers a time-weighted average of 100 ppm over an eight-hour period as the recommended exposure limit.

In space

Ethyl formate has been identified in dust clouds in an area of the Milky Way galaxy called Sagittarius B2[3]. It is among 50 molecular species identified using the 30 metre IRAM radiotelescope.

Chemical properties

Ethyl formate is a simple aliphatic ester that is full of benefits and concerns[3]. It's a clear, slightly oily liquid with a pleasant, rumlike odor and the flavor of raspberries[3]. The ester occurs in many food substances, including fruits, coffee, tea, and grains[3]. The synthetic product is often used as a flavoring agent in lemonade and artificial alcoholic beverages[3]. It is used industrially as a solvent and as a fungicide and larvicide in processed foods such as dried fruits and cereals[3].

In its pure form, ethyl formate has several dangerous properties, including being a flammable liquid and a fire hazard[4]. It can affect you when breathed in and may be absorbed through the skin[4]. Contact can cause skin and eye irritation[4]. Breathing ethyl formate can irritate the nose and throat[4]. Breathing ethyl formate may irritate the lungs causing coughing and/or shortness of breath[4]. Higher exposures can cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency, with severe shortness of breath[4]. Exposure can cause headache, nausea and vomiting[4]. Ethyl formate can affect the nervous system[4].

Safety precautions

When handling ethyl formate, it is recommended to eliminate all ignition sources (no smoking, flares, sparks or flames) from the immediate area[2]. All equipment used when handling the product must be grounded[2]. Do not touch or walk through spilled material[2]. Stop leak if you can do it without risk[2]. Prevent entry into waterways, sewers, basements or confined areas[2]. A vapor-suppressing foam may be used to reduce vapors[2]. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers[2]. Use clean, non-sparking tools to collect absorbed material[2]. For large spills, dike far ahead of liquid spill for later disposal[2]. Water spray may reduce vapor, but may not prevent ignition in closed spaces[2].

Protective clothing and eye protection are recommended to prevent skin contact and eye contact[2]. If contaminated, the worker should immediately wash the skin[2]. Work clothing that becomes wet should be immediately removed due to its flammability hazard[2]. If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids[2]. Get medical attention immediately[2]. If this chemical contacts the skin, water flush immediately[2].

Chemical structure

Ethyl formate has the formula C3H6O2 and a molecular weight of 74.0785[5]. Its IUPAC Standard InChIKey is WBJINCZRORDGAQ-UHFFFAOYSA-N[5].

Citations:

[1] https://en.wikipedia.org/wiki/Ethyl_formate

[2] https://cameochemicals.noaa.gov/chemical/697

[3] https://www.acs.org/molecule-of-the-week/archive/e/ethyl-formate.html

[4] https://nj.gov/health/eoh/rtkweb/documents/fs/0885.pdf

[5] https://webbook.nist.gov/cgi/cbook.cgi?Name=FORMIC+ACID%2C+ETHYL+ESTER&Units=SI