The US government has warned that it is considering imposing anti-dumping tariffs on Asian plastic bag makers.
US shoppers consume a lot of plastic
The US Commerce Department has said it may impose tariffs of up to 123% on Chinese, Malaysian, and Thai plastic shopping bag producers.
The Commerce Department said it would continue its investigation and reach a final decision in June.
The US imported about 100 billion plastic bags in 2002, worth more than $127m, and China supplied about 30%.
The list of items causing trade tensions between the US and Asian countries already includes Vietnamese cat fish and Chinese-made bras and colour TVs.
The Commerce Department issued its preliminary ruling after complaints from US packaging firms, including Sonoco Products and Interplast Group.
They say unfairly cheap Asian plastic bags are losing them $300m in sales a year.
The Commerce Department set out a complex list of penalties, listing different levels of anti-dumping duties for the various Chinese, Thai and Malaysian firms.
China sells more plastic bags to the US than either of the other two countries and its huge trade surplus with the US is causing increasing political friction.
But in the plastic bag dispute, its firms attracted the lowest Commerce Department penalties.
The Chinese firms face potential anti-dumping tariffs ranging from less than 1% to 57%.
Thailand's plastics firms drew the toughest tariffs, ranging from just under 3% to 123%, while the punishment for Malaysian companies was from 0.1% to 102%.
Although the ruling is not final, the Asian firms will start to feel the pinch right away.
They will have to deposit cash up the amount of the potential tariffs when they sell bags to the US, Reuters news agency reported.