San Francisco, California-based US district judge Vince Chhabria, who must approve a future class action plan that is part of the settlement, said he is skeptical and “tentatively inclined” to reject this part of the deal. A hearing is scheduled for Jul 24.

Some 30,000 claims from US plaintiffs who contend that the former Monsanto’s non-selective glyphosate-based herbicide was responsible for their non-Hodgkin’s lymphoma (NHL) are still outstanding, and some lawyers are said to be looking to file new suits that could add tens of thousands to the total.

Any snags in the plans going forward would not legally endanger the body of the $8.8-9.6 billion settlement already agreed with the majority of plaintiffs – this does not require court approval. The uncertainty is concerns the future class agreement for which the German group has budgeted $1.25 billion.

Regarding the cases to be settled in future, the scientific advisory body that William Dodero, Bayer’s global head of litigation, has described as a “blue ribbon panel,” has come in for criticism. Its members would be selected by the parties by mutual agreement, and it would also bring independent experts to weigh in on the chemical’s toxicity.

If the experts found that glyphosate is not a carcinogen, class members would be barred from pressing any more claims against Bayer. But if the panel found that Roundup does cause cancer, the cases could proceed.

Chhabria has asked rhetorically whether it would be constitutional or otherwise lawful to delegate the function of deciding the general question of whether and at what dose Roundup is capable of causing cancer from judges and juries to a panel of scientists.

The judge also has pointed to opinions that the science on glyphosate’s cancer-causing properties is still evolving, and it thus might not pass legal muster to have claimants locked into findings that could be supplanted by a new study.

Bayer has proposed giving the panel four years to study existing research on whether Roundup and its active ingredient, glyphosate, can cause cancer, This has aroused skepticism among commentators who noted that the chemical has been studied for a number of years already, without this question being definitively resolved.

Finally, Chhabria sees procedural drawbacks in making sure that all potential future Roundup claimants have proper notice that they must decide within five months whether to become part of the class, given its “diffuse, contingent and indeterminate nature.”

Plaintiffs who don’t opt out within that timeframe automatically become members of the class.