76 
BULLETIN 1036, U. S. DEPARTMENT OE AGRICULTURE. 
Table 29.— Comparison of the percentages of distillates of the creosotes whose toxicities 
u ere compared by Weiss. 
Fraction. 
Straight 
coal-tar 
creosote. 
Main- 
tenance 
of way 
creosote. 
Upto200°C 6 6 
up to 2.35° c ::;; 6o; 3 
Up to 270° C I 7 6 .5 
Up to 315° C 86.2 
33.2 
60.5 
7S. 
Neutral 
coal-tar 
creosote 
sp.gr. 
1.8 
30.6 
63.4 
87.2 
Water- 
gas-tar 
creosote 
sp.gr. 
1.024. 
1.1 
IS. 9 
50.2 
81.4 
Water- 
gas-tar 
creosote 
sp.gr. 
1.053. 
5.3 
24.3 
49.0 
All the coal-tar creosotes, even the neutral creosote, had lower 
boiling points than the water-gas creosotes, and consequently they 
should be more toxic than the water-gas-tar creosotes. 
Tests made at the Forest Products Laboratory indicate that water- 
gas-tar creosotes, particularly the lower boiling ones, have a con- 
siderable degree of toxicity. A relation of toxicity to volatility 
similar to that found in coal-tar creosotes holds in the case of water- 
gas-tar creosotes also, except that the latter are not as toxic as the 
former, particularly so in the higher boiling oils that are analagous 
to carbolineums. The relation between toxicity of water-gas-tar 
creosotes and their volatility is shown in figure 36. 
^ /oo 
% 
30 
GO 
90 
\ 
1 
i 
V 
V 
■"-^-^ 
*& 
77E* 
?G* 
-<S7 
WP 
ass 
7/ZZ/?7 
25 
P£#C£/VT/?£Q~U//?Ea TQK/U. 
<?o 
£0 
Fig. 36.— The relation between volatility and toxicity of water-gas-tar creosotes. 
