Styrene is considered "bad" primarily due to its classification as a likely human carcinogen and its significant impact on both personal health and the environment. In 2026, health organizations continue to warn that chronic exposure to styrene—often found in the manufacturing of polystyrene (Styrofoam), resins, and rubber—can lead to central nervous system damage, manifesting as headaches, fatigue, and "styrene sickness" (dizziness and loss of coordination). There is also increasing evidence linking long-term inhalation of styrene vapors to an increased risk of leukemia and lymphoma. Environmentally, styrene is a persistent pollutant; Styrofoam products do not biodegrade and often break down into microplastics that contaminate oceans and harm marine life. When these products are incinerated, they can release toxic gases like carbon monoxide and various hydrocarbons into the atmosphere. Due to these risks, many cities globally have banned single-use polystyrene containers, pushing for sustainable alternatives like compostable paper or reusable glass to mitigate the chemical's leaching into food and its long-term presence in our ecosystems.