A group of non-vessel operating common carriers (NVOCCs) have sent an open letter to the International Maritime Organization (IMO) asking how the IMO's 171 member states plan to implement and enforce the upcoming container weight requirements included in the organization's Safety of Life at Sea (SOLAS) treaty.

The members of the "Global Consolidators Working Group," which function in much the same way as ocean freight forwarders, asked the IMO for a "status update" on the requirements, which are scheduled to take effect July 1. Under the requirements, shippers are required to certify in writing the "verified gross mass" (VGM) of a container before it can be loaded aboard a vessel. U.S. exporters have said it is unreasonable for them to certify the total weight of the cargo and container because they don't own or control the equipment.

The Agriculture Transportation Coalition (AgTC), which represents U.S. agriculture and forest-products interests, has advised U.S. shippers to abide by existing law requiring them to submit a container's gross weight, which consists of the weight of just the cargo. Certifying a container's tare, or unloaded, weight would be the responsibility of the ship lines, the group said.

The stance of U.S. shipper interests may have been emboldened by comments last week by Rear Adm. Paul Thomas, assistant commandant of prevention policy for the U.S. Coast Guard, which enforces the safety of U.S. seafaring. In a blog post, Thomas said the Coast Guard has no power to apply SOLAS to U.S. shippers and called on shippers and carriers to work out their own policies to ensure safe and efficient maritime trade.

In a letter to members on Thursday, the AgTC said it took Thomas' comments to mean that the status quo is acceptable and there is "no need for delay or change to the current cargo-weight information flow from shipper to carrier." The group vowed that it would "not agree to submit container weight," nor would it "accept legal liability for those container weights."

The SOLAS amendment has the force of law on the member states. The exporter coalition has called on the U.S. government to delay the amendment's implementation until the country's top 15 trading partners have adopted it. However, Thomas, in his post, said a U.S. delay of the rule's implementation would prevent other nations from loading U.S. cargoes aboard their vessels at U.S. ports, thus putting U.S. exporters at a disadvantage.