Importing Bike Helmets for the US Market
Summary: There are US government regulations that must be met to import a bike helmet for the US market. This page has some indications of where to start looking for info on the regulations that apply specifically to helmets, but does not attempt to cover everything needed to import helmets.
The basic regulatory requirements for importing a bike helmet for sale in the US market are found in the Consumer Product Safety Commission bicycle helmet standard. This is the standard that all bike helmets must meet by law to be sold in the US. It has been modified only once, with a letter to manufacturers interpreting the language on projections.
CPSC has a very helpful Bicycle Helmets Business Guidance page on their website. It has brief explanations of the lab test requirements under the CPSC standard and a link to their Regulatory Robot page, where you input "helmet" and it gives you a complete listing of requirements with explanations and other materials.
The basic premise is that the US importer is responsible for testing the helmets, quality control, documentation and all other requirements. The importer must certify that the helmets meet all applicable regulations. That gives CPSC legal recourse against a US company.
There are also requirements for any product sold in the US that it meet the lead, phthalate and other standards set by the Consumer Product Safety Improvement Act of 2008. A declaration form must accompany any importation of helmets so that customs can verify that the product meets CPSIA. There are regulations for children's products that differ from adult products.
That is just for starters. There are many other import requirements and documentation that we have no knowledge of, and are not attempting to cover here. We recommend starting with the CPSC pages cited above.