If it is a shipping issue, I would be interested to know what new regulation went into effect today that was not in effect yesterday, if any. Then I would know whether to stomp my feet at B&H or the regulators. Somehow these chemicals are being shipped from the factory to B&H and other retailers, including the few remaining brick and mortar retailers across this great land of ours.
I doubt there were any new regulations that went into effect. My guess is based on (there was a url link here which no longer exists).
There is a good chance that there may have only been 1 or 2 certified employees that could sign the necessary paperwork, and maybe he/she/they quit, got fired, promoted, or whatever. B+H also may have realized that if one of the certified employees was out sick, there is a chance that things wouldn't get shipped.
Remember, it costs a company money to have an employee specially certified in anything. If you're that employee, you would want to be paid more for your certification, and rightfully so.
I think they (B+H/Adorama) felt it was easier and less costly to completely abolish shipping of all chemicals and anything that can fall under the IATA rules or within the CFR-49 regulations that could end up costing them thousands in fines if handled incorrectly.
Why so many of the posters in this thread feel that this is a slap in the face to analog customers is beyond me. It was a simple business decision, but I'll bet it wasn't an easy one to make for either company.