Mainstays · Mattress Protectors
Mainstays Cooling Waterproof Fitted Mattress Protector
Avoid until the brand discloses its waterproof chemistry.
The brand provides no public information about the waterproof coating's chemistry or PFAS content. Mattress protectors typically rely on fluorinated water-repellent coating finishes.
The better-graded swap
Casper
Casper Sleep Essential Mattress Topper
75/100 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
Polyurethane or polyester blend with waterproof coating (type unspecified)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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Is Mainstays Cooling Waterproof Fitted non-toxic? What it is made of
This protector combines a polyurethane or polyester blend with an unspecified waterproof coating. The coating chemistry is the critical unknown, conventional waterproof mattress protectors rely on either PFAS-based water-repellent coating (water-repellent coating) finishes or polyurethane membranes that may themselves leach plasticizers. Waterproof Inc. has not publicly disclosed which method is used here, leaving the primary chemical risk unquantified.
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.
Waterproof / stain-resistant treatment
Water-repellent coating treatments have historically used PFAS.
PFAS
Waterproof Inc. does not disclose coating chemistry. Conventional water-repellent coating finishes in budget mattress protectors commonly use PFOA or other PFAS; polyurethane membranes may contain alternative PFAS or non-fluorinated but structurally similar compounds.
Source, ATSDR ↗Phthalates
Polyester-polyurethane blends may contain phthalates or other plasticizers to improve flexibility and coating adhesion. Risk is higher if the product is exposed to heat (perspiration, high humidity, or high room temperature accelerates leaching).
Source, ATSDR ↗Volatile organic compound (VOC) off-gassing
New polyurethane and synthetic polymer coatings commonly emit odors and volatile compounds in the first few weeks. No testing data available for this specific product; brand provides no off-gassing or VOC certification.
Coating degradation and microfiber shedding
Waterproof coatings on budget protectors wear and crack with laundering and body friction over time. Worn or fractured coatings may shed microscopic polymer particles onto the mattress and potentially into the air.
Lack of certifications and third-party testing
No independent safety testing, OEKO-TEX, or allergen certifications are advertised. Without third-party validation, heavy metals, dyes, or residual manufacturing chemicals cannot be ruled out.
The full breakdown
The brand's record and disclosure
Waterproof Inc. maintains silence on PFAS use and does not appear to publish safety testing, certifications (such as OEKO-TEX, GOTS, or third-party waterproofing standards), or material ingredient lists. No major recalls or controversies have surfaced, but absence of transparency is itself a red flag in a product category where waterproofing chemistry directly contacts skin and bedding during sleep.
How it compares in its category
Budget mattress protectors typically use PFAS-based water-repellent coating or unspecified polymer coatings; premium alternatives (e.g., organic cotton with PFOA-free membranes, or certified natural rubber) cost 2-3 times more. This Mainstays product sits in the cost-conscious segment where durability-to-price tradeoffs often mean less rigorous material sourcing and no third-party validation.
If you buy it
Unwrap and air the protector for 24-48 hours in a well-ventilated space before placing on the mattress, to off-gas volatile compounds. Wash in cool water (not hot, which can degrade seams and coating) before first use; use gentle cycle and lay flat to dry. Replace every 3-5 years as waterproof coatings degrade; do not tumble dry or expose to high heat, which accelerates coating breakdown and potential leaching.
What we don’t know
- Basis
- Model estimate, 35% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Mainstays has made none
Formulations change between production runs, so check the current label. How we grade.
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Find an alternative on AmazonMore mattress protectors 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.