The Period Company · Period Underwear
The Period Company- The Thong Period (Sporty Stretch)
Lower PFAS concern; period care absorbs body fluids, not treated for water repellency.
Period underwear made from nylon and elastane blend with no disclosed water-repellent or stain-resistant finish. No PFAS claims or third-party verification available.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Nylon, elastane blend fabric
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What The Period Company- The Thong Period is made of, ingredients and materials
This thong is a nylon and elastane (spandex) blend, common in athletic and period-care underwear because nylon is moisture-wicking and elastane provides stretch recovery. Neither material inherently requires heavy chemical processing in the final garment, though the dye used and any finishing treatments matter. The blend itself is not associated with leaching or degradation concerns during normal wear or washing at typical household temperatures.
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Elastane (spandex) stability and degradation
Elastane degrades over time with exposure to heat, chlorine, and UV light, releasing oligomers into sweat and body fluids. This is a normal material limitation, not unique to this brand, and is managed by proper care (avoiding high heat and chlorine) and timely replacement.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Heavy metals
No azo-dye contamination, lead, or cadmium in dyes have been reported for The Period Company products. Nylon garments can be dyed with either azo or non-azo processes; the brand does not disclose which, but no testing or violation records exist.
Source, FDA ↗Formaldehyde / VOCs
Formaldehyde finishes are not typical in modern athletic or period-care nylon underwear and have not been reported for this product. Standard nylon-elastane blends do not require formaldehyde-based wrinkle-resistance or antimicrobial treatment.
Source, ATSDR ↗Dye migration or bleeding onto skin
No reports of dye transfer or skin reactions specific to The Period Company thongs. Modern nylon dyeing typically fixes dye well; however, any new garment may release trace dye during first wash. Pre-wash in cool water before wear if you have sensitive skin or dye sensitivities.
Flame retardants
Period-care underwear is not treated with flame retardants because it is not classified as sleepwear and does not fall under consumer product flammability standards. No flame-retardant treatment has been reported or is likely for this product.
Source, EPA ↗The full breakdown
The brand's record and disclosure
The Period Company does not publicly disclose detailed chemical composition, certifications (such as OEKO-TEX or GOTS), or testing for restricted substances. No product recalls, formaldehyde violations, or azo-dye contamination have been reported for their garments in public records. The brand's silence on PFAS reflects the category norm for absorbent menstrual products, which are not water-repelled and therefore do not require fluorochemical treatment.
How it compares in its category
Period-care underwear as a category typically avoids the flame-retardant and heavy chemical finishing that concerns traditional sleepwear or furniture textiles. Nylon-elastane blends are standard and perform similarly to competitors like Thinx, Knix, and other leak-proof period brands. Transparency varies widely across the category; many brands similarly do not publish full chemical safety data, making direct comparison difficult.
If you buy it
Wash in cool to warm water and air dry or tumble dry on low to preserve elastane elasticity; avoid hot water and high heat, which can degrade spandex faster. Replace when elastic loses tension or fabric begins to thin, typically after 2-3 years of regular use depending on care. No special precautions are needed for direct skin contact; standard hygiene practices apply. If you have sensitive skin or dye allergies, patch test on a small area first or contact the brand for dye specifications.
What we don’t know
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- The Period Company has made none
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Period Underwear
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- Coating degradation and microparticle shedding
2 hazards checked on this product. See all of them.
Lunapads
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- The brand calls it PFAS-free, which we have not verified
- Microplastic shedding from water-resistant barrier
Aisle
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- The brand calls it PFAS-free, which we have not verified
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2 hazards checked on this product. See all of them.
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.