Solo Review, Is Solo Non-Toxic?
PFAS Authority is a scoring system, not a laboratory. We do not test products ourselves. Grades are model-based, built from published ingredients, materials, certifications, brand disclosures and third-party lab results where they exist. See the rubric.
Across 6 graded products, Solo averages Poor (33/100). On disclosure, the brand says nothing publicly about PFAS. 1 of its products grade Good or better. Grades are model-based estimates, not lab results.
Worth buying from Solo Good or better, safest first
Solo
Cup Company Grips Plastic Cups SQ1830
polystyrene plastic (PS) with grip coating
Polystyrene monomer and oligomer leaching
Polystyrene can leach small amounts of styrene monomers and oligomers into beverages…
Undisclosed grip-coating additives
Solo does not publicly disclose the chemical identity of the grip coating. Typical…
Microplastics
The grip coating can chip, flake, or degrade over the product lifetime, especially with…
Off-gassing and volatile organic compounds
Polystyrene and applied coatings may off-gas volatile organic compounds, especially in…
Low-medium risk. PFAS less likely, but Solo doesn't disclose coating details.
⚠Risky category by default
Graded and flagged Poor and Bad, we’d swap these
Solo
To Go Strawless Cups with Lids
Polystyrene (PS) cup with proprietary water/grease-resistant coating on interior surface
Styrene monomer leaching
Polystyrene can release styrene (a suspected developmental toxicant) when heated…
Coating degradation and particle release
The proprietary water-resistant coating will degrade with normal use (scratches, thermal…
Microplastic generation
Repeated use, washing (if reused), or thermal stress can cause polystyrene to shed…
Medium-high risk. Skip; Solo doesn't disclose coating chemistry, typical of PFAS use.
⚠Waterproof or stain-proof treatment
Solo
Bistro Design Hot Drink Cups Paper
paperboard with unspecified water/grease-resistant coating
PFAS
Solo has not disclosed whether the water-resistant interior coating contains PFAS or…
Polymer coating migration or degradation
If the interior polymer coating is damaged or exposed to prolonged heat above recommended…
Recycled fiber contaminants (if applicable)
If Solo Bistro uses recycled paperboard, incoming fiber may contain trace contaminants…
Ink or dyes in external print
Solo Bistro cups carry colored branding on the exterior. Food-contact regulations…
Medium-high risk. Skip until Solo discloses coating chemistry.
⚠Waterproof or stain-proof treatment
Solo
Dart Container Corporation Solo Cup Polycoated Hot Paper Cups
paper with polycoated (plastic/wax) water barrier
PFAS
Polycoated food-service cups conventionally use fluorinated grease repellents; Dart has…
Plastic/polymer coating degradation over time
Repeated use, microwaving, or contact with hot acidic beverages can crack or degrade the…
Formaldehyde / VOCs
Paper-plastic laminates rely on adhesives; off-gassing is typically minimal in use but…
Microplastics
Mechanical stress, dishwashing (if reused), or thermal cycling can release microparticles…
Medium-high risk. Skip; polycoated cups likely use PFAS-based grease treatment.
⚠Waterproof or stain-proof treatment
Solo
Hot Paper Cups
Paper with grease-resistant/waterproof coating (unspecified)
PFAS
The unspecified interior coating may leach into hot beverages, particularly fatty or…
Thermal degradation of coating
Paper cup coatings can degrade under sustained heat (above 165°F) or when exposed to…
Medium-high risk. Skip if PFAS concerns matter; coating transparency low.
⚠Waterproof or stain-proof treatment
Solo
Bistro Hot/Cold Foam Cups with Lids
Expanded polystyrene foam with unspecified water/grease-resistant coating
PFAS
Expanded polystyrene foam cups require fluorinated water-repellent coatings to prevent…
Polystyrene degradation and microplastic shedding
Foam cups fragment easily when squeezed, heated, or exposed to acidic/fatty liquids.…
Styrene monomer leaching
Polystyrene foam can leach unreacted styrene monomer, especially when in contact with hot…
Medium-high risk. Skip; foam cups commonly use PFAS water barriers.
⚠Waterproof or stain-proof treatment
Every grade uses the same public rubric. How grades work →