Does Dunkin' Coffee Contain Microplastics? Cups, K-Cups, Iced Coffee (2026)

Last updated: June 17, 2026

The Dunkin' hot cup — post-2020 paper, post-foam

For 65+ years Dunkin' hot coffee was served in an expanded polystyrene foam (EPS) cup — the iconic white styrofoam-feel cup with the orange and pink logo. In 2020, Dunkin' completed a global transition to double-walled paper cups in response to environmental pressure on EPS foam.

From a microplastic standpoint, the swap was a net improvement but not an elimination. The original EPS cup leached styrene monomer (an endocrine-disrupting compound classified as “reasonably anticipated to be a human carcinogen” by the US National Toxicology Program), and shed polystyrene microparticles especially at high temperatures. The new paper cup eliminates that styrene migration but replaces it with PE microplastic shedding.

The new Dunkin' paper cup is constructed the same way as every other major-chain paper hot cup:

• Outer paperboard wall — for stiffness and printing.
• Inner paperboard wall — for insulation (double-walled cups eliminate the need for a separate sleeve).
• Polyethylene (PE) inner lining — in direct contact with the hot coffee at 70–85°C.
• Polystyrene or polypropylene lid — drinking surface.

The published research that applies: Ranjan et al. (2021), published in Journal of Hazardous Materials, tested disposable paper cups at 85–90°C for 15 minutes and found approximately 25,000 microplastic particles released per 100 ml. The methodology mirrors normal coffee-drinking conditions. Zhou et al. (2023) confirmed the order-of-magnitude finding and detected nanoplastic fragments below 1 µm.

Iced coffee — the Dunkin' signature drink

Dunkin' sells more iced coffee than hot coffee in most of its US locations across the entire year — a brand- specific quirk that doesn't apply to Starbucks. This matters for microplastic exposure because the iced cup is more plastic- rich than the hot cup:

• Cup body: Clear #5 polypropylene plastic, full body.
• Dome lid: Polypropylene with a straw hole.
• Straw: Polypropylene (Dunkin' rolled out paper straws in some markets but PP straws remain default in others).
• Contact time: Typically 20–45 minutes as ice melts and the drink dilutes — significantly longer than a hot cup hold.
• Acidic contents: Cold brew is more acidic than hot drip; flavoured iced coffees add sugar and cream that compound extraction.

Per Hussain et al. (2023) testing of food-contact polypropylene at extended contact times, per-drink release likely exceeds the hot paper cup figure. The Dunkin' iced coffee plastic cup is the single highest-microplastic-exposure item on the Dunkin' menu.

Original Blend, Donut Shop, and Dunkin' K-Cups

Dunkin'-branded K-Cups (Original Blend, Dunkin' Decaf, Donut Shop, Midnight, French Vanilla, Hazelnut, Caramel) use standard polypropylene K-Cup construction — same body as Green Mountain, Starbucks Pike Place, McCafé, and Newman's Own. Brewed under hot pressurised water at 92–96°C, they fall into the general K-Cup category: tens of thousands of microplastic particles per brew per Diaz-Basantes et al. (2022).

Dunkin' also sells a smaller line of aluminum Nespresso-compatible capsules (Dunkin' Espresso) in some markets. These are aluminum-bodied with a thin food-grade polymer inner liner — cleaner than the K-Cup option but not zero.

See: do K-Cups release microplastics, coffee pod brand ranking, and Nespresso Vertuo vs Original.

Bottled Dunkin' — grocery store iced coffee, espresso shots

Dunkin' sells bottled iced coffee (PET plastic bottle) and bottled iced espresso (PET or glass depending on region) through grocery and convenience stores. These products sit in their packaging for 6–12 weeks between manufacture and consumption.

• PET-bottled iced coffee (Dunkin' Bottled Iced Coffee): polyethylene terephthalate plastic. Cold storage helps limit migration, but transit-warm exposure (warehouses, trucks, store displays) accumulates over weeks.
• Glass-bottled premium iced espresso (specialty Dunkin' lines): glass is inert; check the lid construction — metal twist-top is cleaner than plastic lid.
• Dunkin' Cold Brew bottled multipacks: typically PET; same considerations as bottled iced coffee.

Dunkin' bagged ground coffee and beans

Bagged Dunkin' ground coffee (Original Blend, French Vanilla, Hazelnut) is sold in multi-layer plastic + foil bags. The coffee itself has minimal in-bag contact issue because the contact is cold and brief — the migration risk is from brewing, not storage.

At home, the cleanest Dunkin' setup is:

• Bagged Dunkin' Original Blend ground coffee from the grocery store.
• Brewed in a Moccamaster or other low-plastic drip machine, or pour-over with a metal mesh filter.
• Served in a ceramic mug.

This setup eliminates the paper cup contribution, the K-Cup pod contribution, and the bottled-PET contribution — leaving only the small in-bag storage migration and the drip-machine internal path.

Dunkin' formats ranked by relative microplastic exposure

The 80% reduction swap for Dunkin' daily customers

Bring a personal reusable cup. Most US Dunkin' locations accept reusable cups for hot drinks and offer a small discount depending on location. The DD Perks app also occasionally promotes "bring your own cup" days with bonus rewards.

For iced coffee specifically — the highest-microplastic Dunkin' format — the swap is harder because Dunkin' baristas typically pour into the disposable cup before transferring to a reusable. Ask for the drink to be made in your reusable insulated tumbler directly; this is a barista request, not a corporate policy. Stainless steel tumblers like the Stanley Quencher H2.0, Yeti Rambler, or Hydroflask all work well for iced coffee.

Other practical interventions:

1. Skip the dome lid + straw on iced drinks if you can. Sip from the cup rim with the lid off.
2. Order espresso drinks instead of drip when possible. Espresso has shorter brew-water-to-plastic contact.
3. At home, switch from Dunkin' K-Cups to a stainless reusable pod filled with bagged Dunkin' ground coffee. Cuts pod release by ~95%.
4. Skip the bottled grocery-store Dunkin' products. The 6–12 week PET contact is the worst-case packaged-Dunkin' scenario.

See also: does Starbucks coffee contain microplastics?, microplastics in coffee by brewing method, microplastics in disposable coffee cups, and microplastics in espresso machines.