Tomi · Period Underwear
TomboyX First Line Period Boy Shorts Underwear
Lower PFAS concern; period-care textiles rarely use PFAS, but brand transparency is minimal.
TomboyX period shorts are primarily cotton-based fabric with an absorbent gusset, materials that typically do not require PFAS coatings. However, the brand makes no public PFAS disclosure or certification.
Shop Tomi on Amazon →Material
Cotton blend; absorbent core materials (unspecified)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Category baseline
period care is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
The full breakdown
What it's made of and why it matters
TomboyX First Line is a cotton-blend fabric with an undisclosed absorbent core layer, typical of period underwear construction. The outer cotton blend reduces risk of synthetic chemical leaching compared to full polyester, but the absorbent core material (likely superabsorbent polymer, possibly with additives) is not publicly specified by the brand. Without material transparency, you cannot verify whether the core uses virgin or recycled polymers, or what processing chemicals remain.
The brand's record and disclosure
Tomi (TomboyX parent company) has not published detailed material sourcing, chemical certifications, or manufacturing transparency reports in public records. The brand does not advertise third-party testing (e.g., OEKO-TEX, bluesign) for this product line. This silence is typical for emerging period-care brands but limits your ability to verify production standards or chemical residues.
How it compares in its category
Period underwear as a category carries lower chemical risk than traditional menstrual pads (which often use chlorine bleaching, plastic film, and fragrance). TomboyX's cotton-blend design is comparable to mid-tier alternatives like Knix and Thinx in material approach, though those brands provide more public certifications. Premium brands (Proof, Dear Kate) typically disclose testing results; TomboyX sits in the transparency gap.
If you buy it
Wash before first use to remove any residual dyes or processing chemicals. Launder in warm water with fragrance-free detergent and avoid fabric softener, which can degrade absorbency and leave residues. Replace every 6-12 months or if the core loses absorbency, develops odor that washing does not remove, or shows visible degradation. Air-dry only; heat accelerates polymer breakdown and may release volatile compounds.
Beyond PFAS: other things we checked
Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”
Formaldehyde resins (dye fixing)
Cotton-blend textiles often use formaldehyde-based dyes or resin finishes during manufacturing. No public test data for this product; pre-wash reduces residual exposure.
Azo dyes (synthetic colorants)
Color-fast black or dark dyes on underwear may include azo compounds, which can release aromatic amines under sweat/friction. Tomi does not certify that azo-free dyes are used.
Absorbent core leachables (unidentified polymer)
The core material is not disclosed, preventing verification of monomer residue (e.g., acrylamide) or additives. Period-care cores are rarely tested publicly; extended contact with genital skin warrants caution if product is retained long-term.
Microplastics from synthetic fibers
Blend composition (cotton percentage not specified) may include polyester or other synthetics. Shedding risk is low during wear but increases with laundering; microfiber release into water occurs with repeated washing.
Antimony in polyester (if present)
If polyester is used as a blend component, antimony trioxide catalyst residue is a theoretical risk. No recalls or test reports exist for TomboyX products specifically.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
Safer alternatives in Period Underwear
JAMA Organic
LOLA Organic Cotton Period Underwear
Organic cotton with moisture-wicking gusset
Lower PFAS concern, organic cotton base with no waterproof claims, but brand doesn't explicitly address PFAS.
✓Verified PFAS-free by a third party
JAMA Organic
Organyc Certified Organic Cotton Disposable Period Underwear for Sensitive Skin
certified organic cotton with absorbent core
Lower concern, organic cotton base suggests minimal PFAS risk, but no explicit PFAS statement limits confidence.
✓Verified PFAS-free by a third party
Ruby Love
Women's Hipster Period Underwear
organic cotton with waterproof coating
Lower concern, PFAS-free verified; buy with confidence.
✓Lab test found no PFAS
More period underwear 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.