In the U.S., there are no federal legal requirements for "child suffocation" warnings on plastic bags. However, five states have regulations on suffocation warning for certain plastic bags and each state's regulations and statutes specify the warning statements to be used. In the case of California and Rhode Island, alternative language may be used so long as it is substantially equivalent. In Massachusetts and New York, alternate wording must be approved by the appropriate state agency. Virginia only requires warnings on plastic dry cleaning bags. The example you give includes the same wording as the Massachusetts warning, "WARNING: To avoid danger of suffocation, keep this plastic bag away from babies and children. Do not use this bag in cribs, beds, carriages or play pens. This bag is not a toy." It also includes all the wording of the New York warning and is essentially the same as that required by California and Rhode Island.