Table 8. Eye irritation degree and eye irritation threshold are as shown above. Threshold value of
formaldehyde in our experiments is similar to that reported by Stepehn. Threshold values
of PAN and PBzN are slightly lower than those previously reported. Furthermore,
threshold value of the mixed gase with formaldehyde, PAN, PBzN and 0 3 was found to be
0.14 ppm. It is first reported that eye irritation of compound irritant gases was researched,
in so far as it is known.