I received notification recently that Rely 280 can now be used in California without growers being required to use a closed mixing and loading system.
According to manufacturer representatives, a revised label has been approved by the California Department of Pesticide Regulation and the US-EPA.
Here's a link to the press release for more info and I've pasted below a particularly important paragraph from that press release:
New inventory of Rely 280 herbicide, which will carry the revised labeling allowing product to be used without the closed mixing/loading system requirements, will be available in the marketplace by April. Growers with existing inventory are not required to use a closed mixing/loading system as long as they have a stamped copy of the new label (paper or electronic) in their possession at the application site at the time of application. This is being communicated by CDPR to all the County Agricultural Commissioners.