China has been the world's largest importer of recyclable materials since the 1980s. In 2017, China's Ministry of Ecology and Environment announced an import ban of 24 types of solid waste (later updated to 32 types) including unsorted wastepaper, textiles and plastics. The secondary raw material harvested from the imported waste is expected to be replaced by domestic resources. The import ban is to be implemented in two tiers, with the first 16 types of waste banned by the end of 2018, and the remaining types banned by 2020. On 29 June, China limited the entry points for imported waste into the country to 18 designated river and sea ports, effective 1 January, 2019.