Onia Size M Blue Shadow Ginny Block Mesh One-piece Swimsuit $245
Lower concern; basic nylon swimwear without known PFAS treatment, but brand discloses nothing.
Standard nylon mesh one-piece with no documented water-repellent, stain-resistant, or water-repellent coating finish. Nylon fiber itself poses lower PFAS risk. Onia makes no PFAS-free claims or third-party certifications.
The better-graded swap
Patagonia
Patagonia Women's Bottom Turn Racerback Bikini Top
90/100 safety
Same rubric that flunked this product. The swap earned Excellent.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
nylon mesh (primary fiber)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What Onia Size M Blue Shadow Ginny Block Mesh is made of, ingredients and materials
This swimsuit is constructed primarily from nylon mesh, a synthetic polymer that is chemically stable when used as intended in swimwear. Nylon does not leach significant compounds into skin or water under normal wearing and rinsing conditions. The 'mesh' construction allows water flow and breathability, reducing trapped moisture that could otherwise promote mold or bacterial growth in seams or lining.
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.
Elastic degradation and microfiber shedding
Like all synthetic swimwear, nylon elastane blends (typically used in waistbands and closures) can shed microfibers when degraded by chlorine, salt, or UV exposure. This is a durability rather than acute toxicity concern, but prolonged sun storage or chlorinated pool use accelerates it.
Mold and bacterial growth if wet-stored
Nylon mesh itself resists microbial growth, but poor drying or sealed storage can trap moisture in seams and closures. This is a use-practice risk rather than a material defect; proper air-drying prevents it entirely.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Azo dyes and synthetic colorants
No recalls or safety warnings exist for Onia swimwear dyes. Standard nylon swimwear uses acid dyes that are color-fast and do not migrate onto skin under normal use; the 'Blue Shadow' colorway has no documented issues.
Formaldehyde / VOCs
No formaldehyde contamination has been reported in Onia products or standard nylon swimwear. Formaldehyde risk is primarily associated with wrinkle-resist finishes on cotton apparel, which do not apply to nylon mesh swimwear.
Source, ATSDR ↗Heavy metals
Cadmium, lead, and other heavy metals in synthetic dyes are subject to EU and US apparel regulations. No testing data or recalls implicate Onia products; standard acid dyes used in nylon meet established safety limits.
Source, FDA ↗The full breakdown
The brand's record and disclosure
Onia is a swimwear-focused brand with no major product recalls or documented safety controversies on record. The brand does not publicly disclose detailed materials testing, supplier audits, or PFAS avoidance commitments; this silence reflects an industry norm for mid-tier swimwear rather than a red flag. No independent testing has flagged Onia products for heavy metals, dyes, or restricted chemicals in publicly available sources.
How it compares in its category
Nylon mesh one-piece swimsuits are a standard material choice across price tiers and brands. This product sits in the upper-mid price range (USD 245) without corresponding transparency advantages over lower-cost nylon alternatives. Performance and durability are the main quality differentiators in this category; chemical safety profiles across nylon swimwear are broadly similar absent specific treatment additives.
If you buy it
Rinse thoroughly after each salt-water or chlorinated use to remove mineral residues and chlorine, which can degrade nylon elasticity over time. Store dry in cool shade to prevent elastic breakdown and color fading; avoid prolonged sun exposure when not worn. Replace after 1 to 2 years of regular use or when elastic fails or seams weaken. Do not machine wash or dry; hand wash in cool water with mild detergent.
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
- Onia has made none
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Swimwear
Patagonia
Women's Bottom Turn Racerback Bikini Top
- Nylon/polyester blend with elastane (standard swimwear)
- The brand calls it PFAS-free, which we have not verified
- Elastane (spandex) degradation under heat or chlorine
More swimwear 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.