The determination of parts per billion concentrations of hexamethylphosphoramide and its metabolite, pentamethylphosphoramide, in urine.

Hexamethylphosphoramide (HMPA) possesses unique solvent properties as a solvent in organic and organometallic reactions. Its acute toxicity is low to moderate. Its chronic toxicity is more severe in that inhalation exposure to HMPA vapor concentrations as low as 50 ppb for 12 months produced squamous cell carcinoma of the nasal cavity in laboratory rats. A simple and rapid technique for measuring in urine HMPA and its principal metabolite, pentamethylphosphoramide (PMPA) is described. Twenty mL of 50% (w/v) sodium hydroxide-water solution is added to a 50-mL urine specimen. HMPA and its demethylated metabolite, PMPA, then are extracted from the urine specimen with 5 mL of chloroform. For the nominal concentration range of 10 to 1000 ng/mL, HMPA and PMPA extraction from urine into chloroform averaged 88.0% and 80.2% respectively. The HMPA and PMPA in the extract are assessed by gas chromatography, using a phosphorous flame photometric detector, and quantified by an external standard calibration technique. The limit of detection for HMPA and PMPA in urine is 2 ng/mL. The total analysis time is less than 20 min. The method was validated by analyzing spiked urine samples prepared by another laboratory. Linear regression correlation coefficients greater than 0.99 were obtained for HMPA and PMPA for the 10 to 192 ng/mL concentration range.

Effect of heat stress on physiological factors for industrial workers performing routine work and wearing impermeable vapor-barrier clothing.

The thermal hazards of suits impermeable to water vapor have been documented where fatal heat strokes have occurred during exercise in plastic suits at ambient temperatures as low as 26.7 degrees C. Research has shown that during work with impermeable vapor-barrier clothing (VB) the body temperature rises at a faster rate than without VB clothing. The purpose of this work was to study the effect of wearing VB clothing in hot environments on physiological responses (body temperature and pulse rates) for a group of workers performing routing work and to demonstrate the ease with which meaningful physiological measurements can be made on individual workers. Workers who wore VB clothing reached an extrapolated 37.6 degree C oral temperature at a 2.8 degrees C lower WBGT index that workers not wearing the VB clothing. When work durations in VB clothing exceeded 45 minutes, the oral temperature exceeded 37.6 degrees C. Also, these workers had no recovery pulses rates about 65% of the time after they worked in VB clothing for 15 minutes. The implementation of engineering and administrative controls and the use of a vortex-cooled air suit significantly reduced the stress produced by the physical labor, the VB clothing and the heat exposure.