SOLO Hot Paper Cups
Medium-high risk. Skip if PFAS concerns matter; coating transparency low.
Waterproof and grease-resistant coating on disposable hot cups, historically made with Teflon-family coating-based compounds or aqueous systems containing PFAS. Solo discloses nothing.
The safe swap
Solo
Solo Cup Company Grips Plastic Cups SQ1830
70/100 safety
Same rubric that flunked this product. The swap earned Good.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Paper with grease-resistant/waterproof coating (unspecified)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
Waterproof / stain-resistant treatment
Water-repellent treatments have historically contained PFAS chemicals.
Category baseline
PFAS exposure happens more often with clothing products.
No PFAS disclosure
The company has not publicly discussed PFAS in this product.
PFAS
The unspecified interior coating may leach into hot beverages, particularly fatty or acidic drinks that interact with grease-resistant layers. No published migration testing specific to SOLO cups is available; actual risk depends on coating chemistry, which the manufacturer does not disclose.
Source: ATSDR ↗Thermal degradation of coating
Paper cup coatings can degrade under sustained heat (above 165°F) or when exposed to microwave radiation, potentially releasing monomers or degradation products into beverages. SOLO's typical use case (hot beverages) places it within a temperature range where degradation risk is low but not zero.
What’s reassuring
Microplastics
No documented cases of microplastic shedding from SOLO hot cups or similar paper cup coatings have been reported in scientific literature. Risk is theoretical rather than established for this product category.
Source: EPA ↗Ink or bleach residues on exterior
SOLO cups are printed with water-based or soy-based inks and bleached during manufacturing; migration into beverages is not a recognized concern for standard hot cup use, as exterior printing does not contact liquid.
Allergen or irritant from coating surfactants
Surfactants used to apply or stabilize waterproof coatings could theoretically trigger contact dermatitis in sensitive individuals, but no case reports or recalls linked to SOLO cups exist in public databases.
The full breakdown
What it's made of and why it matters
SOLO hot paper cups consist of virgin fiber paper with a proprietary waterproof and grease-resistant interior coating. The coating's chemical composition is not disclosed by the manufacturer, which is the core safety concern. Most hot paper cup coatings historically used PFAS-based fluorochemicals to repel both water and oil, though some manufacturers have shifted to non-PFAS alternatives; SOLO has not publicly committed to either direction. The coating prevents liquid from saturating the paper structure, but its leaching potential into hot beverages remains unquantified by independent testing.
The brand's record and disclosure
SOLO (owned by Dart Container Corporation) has not released detailed ingredient lists or third-party testing data for their cup coatings. The company has not publicly pledged to eliminate PFAS or adopted certification standards such as Green Seal or Cradle to Cradle that would mandate coating transparency. No recalls or formal safety violations specific to SOLO cups are on public record, but the absence of disclosure is itself a red flag in an industry where competitors are increasingly transparent about coating chemistry.
How it compares in its category
SOLO cups are among the most widely sold disposable hot cups in North America, but their lack of coating disclosure places them in a weaker position compared to brands like Footprint and Notpla, which explicitly market PFAS-free alternatives. Competing products from other major manufacturers (e.g., Huhtamaki, Chinet) similarly lack public coating specifications, making SOLO representative of industry opacity rather than exceptional. Reusable ceramic or stainless steel cups eliminate the coating question entirely but require washing discipline.
If you buy it
Use SOLO cups for beverages at or below 165°F (74°C); do not microwave or expose to extended direct heat, as elevated temperatures may accelerate any leaching from the coating. Replace cups if visible degradation, discoloration, or peeling of the interior coating occurs. If PFAS or fluorochemical exposure is a personal health concern, request detailed ingredient disclosures from SOLO customer service before purchase, or transition to reusable alternatives where feasible. Store unused cups in a cool, dry place away from solvents or oils that could compromise the coating.
What we don’t know
- Basis
- Model estimate, 45% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Solo has made none
Formulations change between production runs, so check the current label. How we grade.
Safer alternatives in Coffee Cups
Eco-Products
World Art Hot Cups 4oz
Plant-based compostable PLA coating
PLA monomer leaching (lactic acid/oligomers)
Limited concern
Compostability claims vs. actual infrastructure
Moderate concern
Coating degradation and exposure over time
Limited concern
Mold or bacterial growth in wet storage
Limited concern
Lower PFAS concern. Brand explicitly avoids PFAS in compostable cups.
⚠Waterproof or stain-proof treatment
Solo
Cup Company Grips Plastic Cups SQ1830
polystyrene plastic (PS) with grip coating
Polystyrene monomer and oligomer leaching
Limited concern
Undisclosed grip-coating additives
Limited concern
Microplastics
Limited concern
Off-gassing and volatile organic compounds
Limited concern
Low-medium risk. PFAS less likely, but Solo doesn't disclose coating details.
⚠Risky category by default
Eco-Products
World Art Renewable Resource Hot Drink Cups
Paperboard with unknown water/grease-resistant coating
Undisclosed water-resistant coating leaching
Limited concern
Coating degradation under thermal stress
Limited concern
Microplastic/fiber shedding from damaged coating
Limited concern
Inadequate compostability if coating is synthetic
Limited concern
Medium-high risk. Skip until coating chemistry is disclosed.
⚠Waterproof or stain-proof treatment
More coffee cups grades
How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.