The Organization for the Prohibition of Chemical Weapons, the implementing body of the Chemical Weapons Convention, has released its interim report on the incident at Douma last April. Here’s a snippet from its findings:
OPCW designated labs conducted analysis of prioritised samples. The results show that no organophosphorous nerve agents or their degradation products were detected in the environmental samples or in the plasma samples taken from alleged casualties.
They did find traces of “chlorinated organic chemicals”, e.g. carbon tetrachloride, chloroform, and certain insecticides, as well as Sucralose and Zoloft.
The OPCW is about as unbiased as can be found, indeed, if anything it’s biased the other way. I think this should be receiving more attention.