McDonald's Styrofoam containers were iconic, lightweight, white polystyrene "clamshell" boxes, famous for the McDLT burger, which had two compartments to keep hot (patty) and cold (lettuce, tomato, cheese) ingredients separate until eaten, preventing sogginess and maintaining temperature. These containers, prized for insulation and cost-effectiveness, were phased out in the 1990s due to environmental concerns, replaced by paper packaging.

Key Characteristics:

Material: Expanded Polystyrene (EPS) foam, known for its lightweight nature and excellent insulation properties.

Design: Often a hinged "clamshell" box with a snap-shut lid, sometimes featuring a squeaky sound when closed.

McDLT Compartments: The most famous design featured two sections: one for the hot bun/patty and another for the cold toppings, plus the top bun, allowing users to combine them.

Nostalgia: Many people remember these containers fondly for keeping food warm and fresh, with some even using the lid for fries or sauce.

History & Discontinuation:

Rise: Introduced in the 1980s (especially with the McDLT in 1984/85) to improve food quality and presentation.

Phase Out: McDonald's began phasing them out in November 1990, responding to environmental concerns about polystyrene's impact on landfills and marine debris.

Legacy: Though gone from most uses, they remain a strong symbol of 80s and early 90s fast-food culture, with only limited use for cold beverages remaining in some areas.