Pyran acute toxicity

In a recent study by Munson, White and KLykken (38), it was reported that the acute toxicity of pyran was a function of salt... 

Table XI. Effect of Molecular Weight of Pyran on Acute Toxicity...

Similar to previous studies, it was shown that as the molecular weight of the polymer fraction decreased, so did the acute toxicity (Table III). Endotoxin sensitization showed a dependence on molecular weight distribution particularly with the more active polymers such as pyran and PAAMA. 

Recently, Munson, et al. [27], reported that the calcium salts of pyran were less toxic than sodium salts. It was also demonstrated that toxicity and sensitization to bacterial endotoxin were molecular weight dependent (Table IV). While the two salts showed differences in acute toxicity, little difference was seen in the sensitization to bacterial endotoxin. 

Ballantyne, B., D.E. Dodd, I.M. Pritts, D.J. Nachreiner, and E.H. Fowler. 1989. Acute vapour inhalation toxicity of acrolein and its influence as a trace contaminant in 2-methyoxy-3,4-dihydro-2H-pyran. Human Toxicol. 8 229-235. 

---