The plasma concentration of HFC-143a increased promptly at start of exposure, and decreased in the same manner post-exposure. A stable level of 4.8 ± 2.0 μM (mean ± S.D.) was reached within 30 min of exposure. The HFC-143a concentration in plasma and exhaled air decreased fast and in parallel when exposure was stopped. The urinary excretion of HFC-143a after exposure was 0.0007%of the inhaled amount. The half-time in urine, calculated from pooled data, was 53 min. The experimental and simulated time courses in blood and exhaled air were in agreement. The simulated relative uptake during the exposure was 1.6 ± 0.3%.
The fibrinogen level in plasma had increased by 11%1 day post-exposure. No statistically significant increase was seen for the other inflammatory markers or for uric acid. No effects of exposure were seen either in the electrocardiographic monitorings or as symptom ratings on the visual analogue scale.