title: Propylene glycol monomethyl ether occupational exposure. 3. Exposure of human volunteers.
abstract: OBJECTIVE
  Propylene glycol monomethyl ether (PGME) is a widely used additive in industrial and consumer products (paints, inks, diluents, cleaning products, cosmetics.). The aim of the present study was to determine uptake and disposition of PGME alpha-isomer in humans.
  
  
  METHODS
  Six healthy male volunteers were exposed to PGME-alpha vapour (15, 50 and 95 ppm) with and without respiratory protection for 6 h including a 30-min break. Free PGME and total PGME (free and conjugated) were analysed in urine. The analytical method involved hydrolysis with HCl (only for the analysis of total PGME in urine), a solid phase extraction on LC-18 columns and a gas chromatograph-flame ionisation detector (GC/FID) analysis after derivatisation with trimethylsilylimidazole.
  
  
  RESULTS
  End-exposure levels of free PGME in urine were found to reach 1.3 (+/-0.3), 4.4 (+/-1.6) and 7.9 (+/-2.5) mg/l for 15, 50 and 95-ppm exposure, respectively, without respiratory protection. End-exposure levels of total PGME in urine were found to reach 2.5 (+/-0.8), 6.2 (+/-1.6) and 10.3 (+/-2.3) mg/l for 15, 50 and 95-ppm exposure respectively. Levels of free PGME were also monitored in exhaled air (0.4 (+/-0.1), 1.4 (+/-0.4) and 2.9 (+/-0.9) ppm at the end of 15, 50 and 95-ppm exposure, respectively) and in blood (2.0 (+/-0.9), 4.9 (+/-2.3) and 11.8 (+/-2.4) mg/l at the end of 15, 50 and 95-ppm exposure, respectively). PGME is rapidly excreted in urine and in exhaled air; the half-lives were calculated to be approximately 3.5 h in urine and 10 min in exhaled air. PGME was below detection limits in breath (<0.1 ppm), in blood (<1 mg/l) and in urine (<1 mg/l) after dermal-only exposure to vapour.
  
  
  CONCLUSIONS
  This study has demonstrated the relatively high pulmonary uptake compared with the dermal uptake. It has also shown the rapid excretion in urine (3.5 h) and in expired air (10 min). With regard to metabolism, this study has established the presence of conjugated PGME in urine.
authors: Institute of Occupational Health Sciences, Bugnon 19, 1005 Lausanne, Switzerland. Anne.Devanthery@inst.hospvd.ch
authors: Anne
authors: A
authors: Devanthéry
authors: Michèle
authors: M
authors: Berode
authors: Pierre-Olivier
authors: PO
authors: Droz
mesh_terms: D000328:Adult; D001944:Breath Tests; D002849:Chromatography, Gas; D006207:Half-Life; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis* / Q000517:prevention & control; D008297:Male; D016273:Occupational Exposure / Q000032:analysis* / Q000517:prevention & control; D011409:Propylene Glycols / Q000652:urine*; D012134:Respiratory Protective Devices
chemical_list: D011409:Propylene Glycols; C005216:propylene glycol methyl ether