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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Link to relevant study record(s)

Description of key information

Short description of key information on bioaccumulation potential result: 
Furfuryl alcohol is rapidly and extensively oxidized to furfural which in turn is converted by oxidative metabolism to furoic acid and excreted in urine as a conjugate with glycine. At high dose levels, the glycine conjugation pathway may saturate and the direct excretion of furoic acid increases. The glycine conjugation pathway involves the intermediate formation of furoyl CoA which is proposed to be interconverted to furanacryloyl CoA followed by excretion as furanacryloylglycine. Consistent with this database in animals, similar toxicokinetic processes occur in humans exposed to furfural with the overall biological half-life following inhalation exposure estimated at 2-2.5 hours.
For the purposes of risk assessment percentage absorption via the oral route is proposed to be 90% and for absorption via dermal and inhalation routes, 100%.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

For furfuryl alcohol, information on absorption, distribution, metabolism and excretion is available on experimental animals. Although there is no EU RAR for furfuryl alcohol, the metabolism and kinetics has been reviewed by JECFA (2001) and are also considered in the EFSA (2004) opinion on furfural. An overview of the information is given below. In summary, furfuryl alcohol is extensively and rapidly oxidised to furfural.

 

Non human data

Furfural and furfuryl alcohol are interconverted in the gut, with oxidation of furfuryl alcohol to furfural and conversion back to furfuryl alcohol mediated by enteric bacteria (EFSA, 2004).  In studies with laboratory animals it has been demonstrated that both furfural and furfuryl alcohol are well absorbed after oral exposure. For consideration of systemic toxicity, it is therefore considered appropriate to read across to studies with furfural e.g. for repeat dose oral, reproductive and developmental endpoints.

Nomeir et al. (1992) demonstrated the comparative metabolism and disposition of furfural and furfuryl alcohol after oral dosing. Rats were dosed with approximately 0.127, 1.15 and 12.5 mg/kg bw furfural or 0.275, 2.75 and 27.5 mg/kg bw furfuryl alcohol. For both furfural and furfuryl alcohol, at least 86% to 89% was absorbed from the gastro-intestinal tract, as indicated by the excretion of radioactivity in urine and in the expired air. Furfural and furfuryl alcohol were extensively metabolised, and the major route of excretion in rats was via urine (~85% of the dose), whereas 2-4% of the dose was excreted in the faeces. About 7% of the dose was recovered as14CO2 from the expired air in rats dosed 12.5 mg/kg bw furfural. Both furfural and furfuryl alcohol showed similar patterns of tissue distribution with highest levels of radioactivity in liver and kidney, and lowest levels in the brain. Tissue concentrations were proportional to the dose.

Identification of radioactivity in the urine demonstrated that no unchanged furfural or furfuryl alcohol was excreted in the urine. The major urinary metabolite was furoylglycine (73-80% of the applied dose), with furanacrylic acid (3-8% of the dose) and furoic acid (1-6% of the dose) as minor metabolites following exposure to either furfural or furfuryl alcohol.

It is of note that similar oxidative metabolism for furfuryl alcohol and furfural has been reported from in vitro studies of rodent nasal tissue (Mainwaring, 2005), however it is unclear what contribution this makes relative to metabolism in the liver.

Human data

Consistent with this database in animals, similar toxicokinetic processes occur in humans exposed to furfural with the overall biological half-life following inhalation exposure estimated at 2-2.5 hours (Flek & Sedivek, 1978).

Percentage absorption

Based on observations on excretion of radioactive metabolites after oral absorption in rats, it can be concluded that furfuryl alcohol will be absorbed almost completely in the gastro-intestinal tract. For risk assessment purposes the oral absorption of furfuryl alcohol is set at 90%, in accordance with the proposed absorption value for furfural (EU RAR, 2008), with comparable oral absorption in rat and human.

Based on observations of similar absorption, metabolism, excretion and distribution of furfural and furfuryl alcohol after oral absorption and in the absence of additional data, for risk assessment purposes the proposed dermal and inhalation absorption are the same as those proposed for furfural i. e. 100% for both. For inhalation, this is based on information on excretion of radioactive metabolites and lung retention after inhalation of furfural vapour in humans and is in accordance with the RAR for furfural (EU RAR, 2008). For the dermal route, exposure of humans to furfural vapour or to furfural liquid resulted in significant dermal uptake and for risk assessment purposes dermal absorption is proposed at 100% (in accordance with the EU RAR (2008) for furfural). 

 

Additional reference

EFSA (2004): Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food on a request from the Commission related to Furfural and Furfural Diethylacetal.  Question number EFSA-Q-2003-236; The EFSA Journal (2004) 67, 1-27