Sigma · Waterproof Camera & Lens Protection Cases
Sigma WR CPL Circular Polarizer Filter
Lower concern. Optical filters rarely require PFAS; brand does not comment.
This circular polarizer uses optical glass and coatings standard for lens optics. Sigma makes no public PFAS claims or disclosures, and no industry standard exists for PFAS in camera filters.
The better-graded swap
GoPro
GoPro Hero 3+ 4 Underwater Lens Filter Kit
85/100 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
Optical glass, aluminum frame, likely multi-coated lens elements
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Sigma WR CPL Circular Polarizer Filter is made of, ingredients and materials
Sigma WR CPL filters consist of optical-grade glass lens elements (typically borosilicate or soda-lime glass coated with anti-reflective multi-layer dielectric coatings) mounted in an aluminum alloy frame. The circular polarizer design uses crossed polarizing films sealed between glass layers. These are inert, non-leaching materials with no thermal or chemical exposure risk during normal use as a camera accessory.
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.
Unknown / proprietary coating
A coating is recorded with no disclosed chemistry.
Glass breakage and sharp edges
Drops or impacts can shatter the filter glass, creating sharp fragments. Risk is mechanical, not chemical, but mishandling can cause minor cuts when cleaning broken pieces.
What’s reassuring
Coating delamination and inhalation of coating particles
Multi-layer dielectric coatings on optical glass are typically inorganic oxides (silicon dioxide, titanium dioxide, zirconium oxide) that do not flake or off-gas under normal use. No documented cases of coating failure in Sigma WR filters.
Aluminum frame corrosion and leaching
Aluminum frames are anodized or sealed to prevent oxidation and do not come into contact with skin, food, or consumables. No pathways for leaching or absorption in camera filter use.
Polarizing film degradation
Polarizing films are sealed within glass and do not degrade under normal indoor or outdoor use conditions at camera operating temperatures. No known issues with Sigma's CPL film stability or light exposure breakdown.
Heavy metals
Optical-grade coatings do not use lead, cadmium, or antimony; inorganic oxide layers are non-toxic when sealed and immobilized on glass surfaces. No regulatory concerns documented.
Source, FDA ↗How is this PFAS grade calculated?
The brand's record and disclosure
Sigma Corporation (Japan) manufactures optics and camera lenses with no significant public safety controversies or product recalls related to filter construction. The brand has not published formal PFAS or chemical disclosure statements specific to filters, which is typical for optical accessory makers. No evidence of formaldehyde, heavy metals, or restricted coatings in documented product specifications.
How it compares in its category
Optical filters from established makers (Sigma, Hoya, B+W, Zeiss) rely on similar glass and aluminum construction and carry equivalent low-risk profiles. Unlike ceramic cookware or textiles, filters require no contact with skin, food, or water, eliminating leaching and degradation pathways. Third-party optical brands are generally better documented for material safety than unbranded or novelty filter sources.
If you buy it
Store the filter in a protective pouch or case to prevent dust accumulation and coating scratches. Avoid extreme temperature swings (leave in a cold car overnight, then immediately use indoors) which can stress glass-to-metal seals over decades. Clean the glass surfaces only with microfiber cloths and optical-grade cleaning fluid; never use household cleaners. If coating becomes visibly scratched or delaminated, replace the filter rather than use it, as damaged coatings can reduce image quality.
What is not known about PFAS in this product?
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Sigma has made none
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to Sigma WR CPL Circular Polarizer Filter?
- Optical glass lens with multi-coated optical surfaces
- We found no PFAS statement from the brand
- No PFAS statement found from the brand
- Glass lens (borosilicate or soda-lime glass)
- Optical coating degradation
2 hazards checked on this product, all on its full breakdown.
- Optical glass, aluminum frame, non-coated optical surfaces
- We found no PFAS statement from the brand
- Optical glass fragility and sharp edges
More waterproof camera & lens protection cases 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.