Bending the Curve on Polystyrene – Another Poison Plastic

Don’t you hate opening that box only to find your new product surrounded by those annoying foam packaging peanuts that cling to everything? Or, just as bad, those bulky foam blocks that won’t fit in your kitchen trash can? And what’s there to love about those foam coffee cups and food containers that litter the roadside?

The global production of all plastics grew by more than 50% in the last decade. But here’s some good news for a change. Polystyrene is the only major plastic whose production and domestic use are steadily declining. Let’s examine why.

All that plastic foam is made of expanded polystyrene (EPS), commonly called styrofoam. (A registered trademark of DuPont via Dow Chemical, Styrofoam^TM refers only to their own foam insulation board and related products, not EPS in general.)

Consumers also encounter rigid polystyrene (PS) in two forms. General purpose polystyrene (GPPS) is a clear or colored plastic imprinted with the #6 resin identification code. Think cheap disposable food service ware – plastic cutlery, cups, plates, and bowls – and food packaging in clear clamshells, small yogurt cups, and egg cartons. High impact polystyrene (HIPS) makes up the plastic housing of some computers and consumer electronics, cases for compact discs, and parts for toys, appliances, and automobiles.

More than half of all polystyrene becomes waste after a single use. It’s neither recyclable in practice nor compostable, according to a 2023 finding by the State of California. But polystyrene leaves more than just unsightly litter in its wake. It’s also a poison plastic.

Polystyrene plastic harms human health, racial justice, and climate progress across its lifecycle from fossil resource extraction through final disposal. By understanding what’s driving the polystyrene decline, the transition to safer, more sustainable materials can be sped up. These lessons can help replace non-essential uses of all petrochemical plastics.

In the last dozen years, polystyrene plastic production has plummeted by 31%, according to the latest annual report of the ACC Plastics Industry Producers’ Statistics Group, as compiled by Vault Consulting, LLC. The use of PS resin to make food packaging and food serviceware, which accounts for two-thirds of all use, has dropped by 27% since 2016.  Domestic production of EPS foam and its use in packaging has plunged by 25% and 35% respectively over the last two years, according to ACC.

Four factors are driving this market movement away from polystyrene plastic.

1. Corporate Policy

The highest-volume reductions in polystyrene use have been driven by major downstream manufacturers, retail chains, and other brand owners to implement corporate policies to eliminate, substitute, or redesign packaging to be recyclable or compostable. Since polystyrene is neither, reducing its use cuts both plastic waste and greenhouse gas emissions from their supply chain. For example, Ahold Delhaize, a multinational retail grocer (with U.S. brands that include Food Lion, Stop & Shop, and Hannaford) recently switched from a polystyrene clamshell package to a combination of molded fiber (made from compostable pulp) and PET plastic.

But early adoption by market leaders is not enough. That’s why we need widespread adoption of corporate policies to end the use of polystyrene and other plastics.

2. Public Policy

Many laws enacted at the state and local level in the United States and in other countries are driving reductions in the use of EPS foam. Twelve U.S. states have passed laws to phase out specific uses of expanded polystyrene foam, as have more than 250 local governments in twelve other U.S. states. These policies prohibit the sale of foam food service ware, such as hot and cold cups and take-out food containers. Several ban foam trays used for sale of raw meat and seafood, and foam coolers. Some laws also phase out foam loose-fill packaging (i.e. packing peanuts). The City of San Diego also prohibits beach or pool toys, dock floats, mooring buoys, and anchor or navigation markers made of EPS foam that’s not fully enclosed by another material. Five state policies don’t take effect until 2025 so more reductions are expected.

But these laws apply to less than half the U.S. population, leaving many states unprotected from polystyrene waste, including Texas and Louisiana which bear the brunt of production impacts. That’s why we need to accelerate the pace of state policy making and urge Congress to pass The Farewell to Foam Act of 2023 to advance similar policies nationwide.

3. Third-Party Standards

Many market leaders voluntarily commit to meet third-party standards, another type of policy that certifies high performance and the leading edge of change. The U.S. Plastics Pact adopted a list of unnecessary and problematic materials to eliminate that includes all polystyrene used in packaging. Adopted in January 2022 by a multistakeholder industry-dominated group, this voluntary standard spurred legislative proposals in 2023 in California and Maine that fell short of initial passage. Polystyrene also fails to meet the GreenScreen Certified Standard for Single-Use Food Service Ware due to its lack of recyclability and the presence of residual styrene and other petrochemicals of high concern above 100 parts per million.

Currently, these standards have limited reach. More efforts are needed to enroll companies in making serious voluntary commitments and reporting their results.

4. Dematerialization

The rise of digital streaming services for music and video has radically disrupted the market for compact discs. Plastic CD cases are made from polystyrene. (CDs themselves are made of polycarbonate, another problem plastic.) The U.S. sale of CD albums peaked at almost one billion units in 2000, dropping to about 40 million units in 2021, a 96% reduction. This slashed annual use of polystyrene by about 76 million pounds for more than 20 years. Further, the miniaturization of electronics has reduced polystyrene use for plastic enclosures used to encase televisions, computers and other consumer products.

The rise of the digital economy and other technology changes have the potential to further reduce the use of polystyrene and other plastics. But more intentional efforts are needed to identify which technology trends can be promoted and how to accelerate this transition.

Why does all this matter? Billion pounds of polystyrene are still being produced in North America and globally. That means that much work remains to avoid associated impacts.

HEALTH

Some consumers are rightly concerned about exposure to residual styrene from food contact with polystyrene. A typical polystyrene yogurt container or food tray may contain up to 425 parts per million of thirty different petrochemicals, including the carcinogens styrene, ethylbenzene, and cumene; and toluene, a developmental toxicant. These substances are known to migrate from the polystyrene plastic into food and beverages, exposing consumers to hazardous chemicals and others of unknown concern.

But the health hazards of polystyrene production are much greater. That’s why a life-cycle approach must be taken to reduce the adverse health impacts of polystyrene.

The production of polystyrene poses significant chemical hazards to human health especially to workers at oil refineries and styrene plants but also to occupational non-users (others who work nearby) and fenceline community residents.

Three cancer-causing chemicals are used to make polystyrene plastic: benzene, ethylbenzene, and styrene. Other chemicals of concern are used as polystyrene additives or processing aids.

Polystyrene plastic production drives nearly one-third of all benzene use and exposure, more than any other end-use. More than half of all benzene produced at oil refineries is used to manufacture ethylbenzene to make styrene. About 60% of all styrene is consumed to make polystyrene plastic resin and foam.

Benzene exposure causes cancer in humans, including various leukemias and lymphomas, and is a known blood toxicant. There’s strong evidence that workers exposed to benzene contract leukemia at higher rates than unexposed workers. Community exposure to benzene is often unacceptably high at the fenceline of some oil refineries and styrene chemical plants, posing both short- and long-term health hazards.

Ethylbenzene is possibly carcinogenic to humans since it’s been proven to cause kidney, lung and liver cancers in laboratory animals. Studies of exposed workers have been complicated due to concurrent exposures to benzene.

Styrene is reasonably anticipated to cause cancer in humans. There’s some evidence that styrene causes leukemias and lymphomas in workers who use unsaturated polyester resins with glass-fiber reinforcement to make boats, building products, and other plastic items. (Styrene makes up to 35% of polyester resins.) Styrene causes cancer in lab animals and its mechanism of toxicity provides additional supporting evidence of harm.

Styrene production can also result in runaway chemical reactions that have killed or injured workers and polluted the environment in the past. The industry now adds toxic chemicals to styrene to inhibit the likelihood of more catastrophic chemical releases.

The only way to solve the health hazards of polystyrene is to reduce its use and production.

CLIMATE

Plastics, including polystyrene, are a growing threat to our climate. Industrial manufacturing sources account for nearly one-third of all greenhouse gas emissions. The chemical industry along with cement and steel are the biggest industrial climate polluters.

Polystyrene alone accounts for about 6% of the greenhouse gas emissions from primary plastics production, according to a new report from the Lawrence Berkeley National Laboratory (LBNL). Polystyrene is sourced entirely from crude oil and natural gas, clearly unsustainable fossil resources. Three-quarters of the fossil carbon in polystyrene comes from crude oil with the other quarter from natural gas. None of the polystyrene currently on the market is bio-based (i.e., containing renewable carbon recently captured through photosynthesis by living plants).

By 2050, greenhouse gas emissions from plastics could account for 20% to 30% of the entire carbon budget, according to the LBNL report. That’s the greenhouse gas limit needed to give us a fighting chance to keep global warming below the 1.5 degree C temperature increase over pre-industrial levels that could trigger catastrophic impacts.

Today, about 12% of crude oil and 8.5% of fossil gas are used to make plastics, according to LBNL. But plastics production could consume 55% of oil and gas demand by 2050, if production trends are left unchecked, according to the International Energy Agency.

About eighty percent of all petrochemicals are used to make plastics. Production of plastics emits greenhouse gases from the burning of fossil fuels for heat and power. Typically, about 70% of the fossil carbon feedstock is incorporated into the final plastic while nearly one-third of the carbon input is burned to power the process.

Plastic production has increased ten-fold since 1975 and some project a doubling again by 2040. Plastics may be the only economic sector with a rapidly growing carbon footprint.

The prospects for replacing the fossil carbon in polystyrene with renewable carbon are dismal. That’s why ending polystyrene use is only way to avoid its climate impacts.

JUSTICE

Frontline communities that live near oil refineries, petrochemical plants, and plastics production facilities commonly suffer from environmental injustice marked by serious racial and income disparities in exposure to plastics-related hazards.

The chemical footprint of polystyrene plastic demonstrates this same disproportionate impact on communities of color, indigenous nations, and lower income residents.

In the United States, the chemical supply chain of polystyrene plastic consists of about 30 petrochemical plants. People of color make up about 57% of the nearly 700,000 people who live within three miles of these industrial facilities. By comparison, the proportion of people of color nationally is a little more than 40%. A somewhat higher proportion of lower income residents also live within three miles of a polystyrene-related industrial plant (31%) compared to the national average (28%).

In Canada, the Aamjiwnaang First Nation cited the INEOS styrene plant for exposing its citizens to excessively high levels of benzene. This First Nation has suffered for decades from petrochemical pollution in the Chemical Valley of present-day Sarnia, Ontario. They convinced the federal and provincial governments to shutter the INEOS plant unless and until proper benzene controls were installed, a major environmental justice victory.

The use of polystyrene plastic contributes to a legacy of environmental racism, especially on the Gulf Coast of Texas and Louisiana where six large styrene production plants are located. Its continued use should be considered environmentally unjust.

Phasing down styrene use and production while providing a just transition for chemical workers and dependent communities will bend the arc toward justice.

CONCLUSION

Significant reductions in polystyrene use have been realized over the last decade, with the pace of change picking up in the last two years. But many unnecessary and problematic uses of polystyrene continue unabated.

Many safer and more sustainable alternatives are available to replace most uses of polystyrene resin and foam. Such uses are non-essential, following the essential-use approach for chemicals management, which should be applied to the lifecycle of petrochemical plastics. Because of its impacts on human health, climate progress and racial justice, the remaining non-essential uses of polystyrene should be phased out.