MSDS toxic info on Nitrobenzene:
Highly toxic. May be fatal if inhaled, swallowed, or absorbed through skin. Possible carcinogen. May cause reproductive disorders Skin and respiratory irritant. Typical PEL 1 ppm.
MSDS toxic info for Nitromethane:
Harmful if swallowed, inhaled or absorbed through skin. Irritant. May cause cyanosis, which can be delayed up to 4 hours. Typical TLV 100 ppm.
As a matter of comparison, gasoline in this country the best I can find because of variations has a TWA of 10 ppm
Methyl Alcohol: 200 ppm TWA; 260 mg/m3 TWA
Castor oil has no value set... May cause eye irritation. May act as an allergen.
So this means to me that nitrobenzene is 100 times more toxic than nitromethane? But all this also says that nitromethane is twice as toxic as methyl alcohol and so on.
Enjoy,
Jim