"Not a high level of expertise to produce Sarin so could have been produced by either side."

From Reuters:

"Mr Sellstrom confirmed that the quality of the sarin was superior both to that used in the Tokyo subway but also to that used by Iraq during the Iraq-Iran war," he told reporters.

"This does not point to a cottage industry chemical," said Lyall Grant, taking a swipe at earlier comments by Churkin. Churkin said in July that a Moscow analysis found "cottage industry" quality sarin gas was used in an alleged March 19 attack, which he blamed on the rebels."