To provide a glimpse of what kind of fun I get to have in process safety, I wanted to start a series of chemical profiles of some of the nasty hazardous materials I work with and why so many of my clients are such sticklers for meeting all of the different codes/standards/RAGAGEPS to the letter in the design, construction and maintenance of their process(s). Let’s face it, some of these chemicals we may not get a 2nd chance. One such chemical I began working with during my time at Great Lakes Chemical is Furan (Cas# 110-00-9). Furan is a Category 1 Flammable Liquid, one of the true flammable liquids that carry an NFPA Flammability rating of 4. I have only worked with two flammable LIQUIDS that rise to an NFPA 704 Diamond Flammability rating of a 4: Furan and Trichlorosilane (Semi-Conductor business). There just are not a lot of CAT 1 Flammable Liquids. But Furan beat our Trichlorosilane because not only are they both CAT 1 Flammable Liquids, Furan has an IDLH of 13 ppm!! That folks is what I call the double-whammy! EXTREMELY FLAMMABLE and EXTREMELY TOXIC. So let’s look at Furan and the hazards it presents:
It’s Flash Point (FP) is MINUS 31ºF (-31ºF) and it’s Boiling Point (BP) is 88ºF, thus it is a CAT 1 Flammable Liquid and an NFPA Flammability 4.
It’s Minimum Ignition Energy (MIE) is just 0.22 mJ. Remember, when we get shocked by a door in the winter time, that is around 10-15 mJ. So 0.22 mJ is an EXTREMELY LOW MIE and static electricity is a SERIOUS concern when working with Furan.
It has an LEL of 2% and a UEL of 14%, so a low LEL but a relatively narrow flammable range.
It has a Vapor Pressure (VP) of around 500 mm Hg.
Basically, it will be released as a liquid, but it “flashes off” into a vapor QUICKLY and only needs to reach 2% (20,000 ppm) until it will flash when it finds even the smallest of ignition sources, such as static.
But if it does not flash on us, we have to worry about its incredible low IDLH of just 13 ppm. In comparison, Chlorine’s IDLH is 10 ppm.
But it gets better…
From CAMEO we see the following:
Air & Water Reactions:
Highly flammable. When UNINHIBITED, this compound forms explosive peroxides on exposure to air. Insoluble in water. This is what drives the NFPA Reactivity rating of 1.
Fire Hazard: Very dangerous, upon exposure to heat or flame. It may form unstable peroxides on exposure to air. Contact with acids can initiate a violent, heat-producing reaction. Avoid acids, oxidizing agents. Upon standing in air, it may form unstable peroxides. (EPA, 1998)
Health Hazard: The vapors are narcotic. Acute exposure to furan by inhalation may involve both reversible and irreversible changes. Acute exposure by ingestion or skin absorption, as well as chronic exposure, are associated with high toxicity. (EPA, 1998)
Reactivity Profile: FURAN is sensitive to heat and may turn brown upon standing. This compound may be light sensitive. When uninhibited, this compound forms explosive peroxides on exposure to air. This chemical may react with oxidizers, acids, peroxides and oxygen. It resinifies on evaporation or when in contact with mineral acids, but it is stable in alkalis. (NTP, 1992).