Country has changed definition of waste, which campaigners fear could lead to imports of low-grade plastic scraps

Argentina has changed its definition of waste in a move that could allow it to import millions of tonnes of plastic waste discarded in the US.

The country’s president, Mauricio Macri, signed a decree in August reclassifying some materials destined for recycling as commodities instead of waste, allowing looser oversight of mixed and contaminated plastic scraps that are difficult to process, and are often dumped or incinerated.

Social and environmental groups say the decree is illegal and bucks a global trend toward improving controls over waste imports. They worry it could be the first step towards Argentina taking in the plastics that have flooded developed nations after China began to refuse all but the cleanest of shipments in late 2017.

Jim Puckett, the executive director of the Basel Action Network, a group that fights the export of toxic waste from industrialised societies to developing nations, said: “They’re willing to become a sacrificial country where the rest of the world could send their waste and they could profit from it.”

Argentinian environment official Alejandra Acosta said advocates are misunderstanding the decree and that it would actually be more stringent than previous policies, although she could not explain why multiple groups are interpreting the change as relaxing plastic import rules. She acknowledged the government did not do enough outreach with advocates and argued that no mixed plastics or plastics destined for “final disposal” or “energy recovery” via incineration would be allowed.

More than 180 countries are party to the Basel convention, which governs the international waste trade, but the US is not.

Under a recent amendment proposed by Norway, developed nations will not be able to export low-quality plastic waste to developing nations without getting their explicit consent and ensuring the waste can be appropriately handled.

The amendments aim to ensure that even abstaining countries, such as the US, follow the Basel convention rules when sending plastic waste to poorer countries.

Basel convention countries could still strike separate agreements with the US, as long as they ensure that any plastics they receive will not be disposed of in ways that harm the environment and violate the convention, said Pål Spillum, the deputy director general of Norway’s environment ministry.

Acosta argued that Argentina wanted more stringent policies than Norway did, although advocates following the negotiations said Argentina was set on undercutting the strengthening of the convention.

Because of that stance and the new decree, Puckett said he worries that Argentina wants to start taking in America’s waste.

It is thought Argentina could fill the void left by China’s decision to stop accepting all but the easiest-to-recycle plastics from the US, the UK and Europe.

After that change, in late 2017, US plastic waste first began to flow to countries including Vietnam, Malaysia and Thailand. When those countries started to ban the imports, they showed up in Cambodia, Laos, Ghana, Ethiopia, Kenya and Senegal, which previously handled virtually no US plastic, as revealed in a Guardian investigation.

Spillum said his country’s proposal was meant to “increase the control of transboundary movement of plastic waste which is not easily recyclable, and therefore likely to become an environmental problem in the country of import”.

A spokesperson for the US Environmental Protection Agency said the US supported the Basel convention but opposed the amendments.

For plastic scrap to be exempt from the amendments, it would need to “meet a very narrow and strict set of criteria that is difficult and costly to satisfy”, the EPA spokesperson argued, continuing: “The United States is concerned that barriers to the responsible movement of plastic scrap for recycling will decrease its value and make virgin plastics more attractive by comparison, likely increasing the overall volume of disposal of plastics from the waste stream.”

The EPA said it had “just become aware” of Argentina’s new waste decree and had not had a chance to assess its impacts.

Cecilia Allen, a Buenos Aires-based advocate with the Global Alliance for Incinerator Alternatives, said any mixed plastics Argentina accepted from abroad were unlikely to be recycled.

In recent months, the value of recycled plastic has declined. It is more expensive to make than the virgin plastic produced from the ethane gas pulled from underground by oil and gas drillers.

“One of the concerns we have is this can boost an incinerator industry in the country, or waste burning in cement plants,” Allen said. “We have a lot of waste here and we are not reducing, we are not recycling, we are not composting. And it makes no sense for us to open the door for more to come.”

Incinerators that burn plastic are linked to major health problems from the air pollution they produce.

Waste pickers in Argentina, who sift through piles of plastics to collect those that are deemed worth recycling, have protested against the decree, as it is expected to decrease the value of the domestic plastics they retrieve.

Carolina Palacio, a representative for the Argentinian waste pickers federation, said the union has fought for better working and living conditions.

“Instead of this, they deregulate and bring waste from other parts of the world. Don’t we have enough waste here?” Palacio said.

• This article was updated on 4 November 20119 to add a response from the Argentinian government.