While some research has argued that TFA has low health risks , other studies have shown mild liver hypertrophy in rats, and eye and skin irritation . As the levels of TFA are rapidly increasing, some EU countries have proposed to ban HFOs as part of the broad PFAS restriction under REACH. In summary, although the Montreal Protocol is often considered the most successful multilateral environmental agreement, this has led to burden shifting over time from ODS to the production of persistent, mobile substances such as TFA.