Benzene poisoning sources

C150-1-03 and C150-4-03 catalysts were loaded into the small dualtube reactor. The unit was equipped with inlet saturators which served as the source of benzene. Poison levels of 0-5% were tested. The findings... 

Unbumt gasoline and cracked hydrocarbons such as ethylene and propylene are also substantial constituents of exhaust. Gasoline contains additives such as benzene, toluene and branched hydrocarbons to achieve the necessary octane numbers. The direct emission of these volatile compounds, e.g. at gas stations, is a significant source of air pollution. Leaded fuels, containing antiknock additions such as tetra-ethyl-lead, have been abandoned because lead poisons both human beings and the three-way exhaust catalyst, especially for the removal of NO by rhodium. 

Benzene can be absorbed through the skin although the more common route of poisoning is by inhalation. Operators should have regular blood tests and if any signs of a drop or a low level of either red or white cells is observed these tests should be made monthly and the operator should be kept away from any source of exposure. 

Some liquids, e.g. benzene, have a cumulative poisonous effect and others can be harmful above certain concentrations in the air. The smell of a liquid may be enough to prevent its use for some purposes. Smell is largely a matter of customer s opinion, but toxicity information is obtainable from the sources quoted in the Appendix. 

---