No.4 BOND MAINTENANCE SHAMPOO
Low-medium risk. Standard shampoo with no known PFAS triggers.
No.4 Bond Maintenance is a liquid shampoo without water-repellent or stain-resistant claims requiring PFAS treatment. It contains conventional conditioning polymers and surfactants without flagged PFAS materials. Olaplex offers no PFAS-free claims or third-party certifications.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Aqueous surfactant blend, conditioning polymers, water
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
No PFAS disclosure
The company has not publicly discussed PFAS in this product.
Category baseline
cosmetics is a category where PFAS exposure is more common.
1,4-dioxane (rinse-off cosmetic contaminant)
Aqueous cosmetics can harbor trace 1,4-dioxane from surfactant synthesis if not vacuum-stripped during manufacture. Olaplex does not publicly disclose 1,4-dioxane testing or removal protocols; rinse-off exposure is low but not zero. This is a process impurity, not an intentional ingredient.
Formaldehyde / VOCs
Aqueous shampoos require preservative systems to prevent bacterial and mold growth; Olaplex's full preservative package is not disclosed on the label or website. Some preservatives release trace formaldehyde, though rinse-off products present lower systemic risk than leave-on cosmetics. No independent testing results for this product are publicly available.
Source: ATSDR ↗Fragrance allergens (undisclosed constituents)
No.4 contains fragrance listed as a single ingredient, but the actual composition of fragrance compounds is proprietary and not itemized. Individuals with sensitivity to fragrance or limonene-derived terpenes may experience scalp irritation; patch testing on a small area is prudent if you have a history of cosmetic sensitivities.
Polymer buildup and scalp irritation with infrequent rinsing
Premium conditioning shampoos can accumulate on hair and scalp if not rinsed thoroughly or if used daily without clarifying treatments; user reviews and salon professionals have noted occasional flaking or greasy residue with improper use. This is a use-dependent issue, not a formulation defect.
What’s reassuring
Safe base material
Made from ceramic, mineral, or natural fiber with no PFAS risk.
Heavy metals
No.4 is a clear or translucent rinse-off shampoo without pigments or lakes that concentrate lead, cadmium, or arsenic. Conditioning polymers themselves do not typically contain heavy metals unless sourced from contaminated raw materials, and no testing results or recalls indicate this product does.
Source: FDA ↗The full breakdown
What it's made of and why it matters
No.4 is an aqueous surfactant blend with conditioning polymers typical of premium bond-care shampoos, designed to coat and protect chemically treated hair. The formula contains water as the base solvent, anionic surfactants for cleansing, and polymeric conditioning agents (likely silicones or synthetic polymers) to reduce frizz and improve manageability. This material class carries minimal leaching risk because it is meant to rinse away and does not contact skin for extended periods, and aqueous formulations do not concentrate heavy metals the way pigmented cosmetics do.
The brand's record and disclosure
Olaplex has built its reputation on bond-repair chemistry and marketing to professional stylists and consumers seeking damage-control products; the brand does not publish comprehensive ingredient sourcing, heavy metal testing, or PFAS avoidance commitments on its website or packaging. No recalls or safety controversies specific to No.4 have been publicly documented. The brand is owned by Olaplex Holdings Inc. and operates under standard cosmetic safety regulations (FDA oversight in the US, EU Cosmetics Regulation in Europe) but does not voluntarily exceed baseline disclosure standards.
How it compares in its category
Premium bond-care and color-safe shampoos like No.4 occupy a middle tier: they cost more than mass-market sulfate-free shampoos but less than salon-exclusive lines, and they emphasize polymer conditioning over natural oils. Compared to sulfate-based drugstore shampoos, it carries lower skin irritation risk because it uses gentler surfactants; compared to certified organic or heavy-metal-tested brands (e.g., those with third-party testing badges), Olaplex provides no independent safety verification. It is broadly comparable in composition and safety profile to other prestige color-care brands like Amika or K18.
If you buy it
Apply to wet hair, lather, and rinse thoroughly with cool water to minimize polymer buildup and frizz; do not use on broken skin or near eyes. Store away from heat and direct sunlight to preserve polymer integrity and prevent premature degradation. Replace the bottle every 6 to 12 months depending on use frequency; old shampoo may separate or lose conditioning efficacy. Discontinue use if scalp irritation, rash, or unusual hair breakage occurs, though such reactions are uncommon with this formulation.
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
- Olaplex has made none
Formulations change between production runs, so check the current label. How we grade.
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Puracy
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1,4-dioxane (surfactant byproduct)
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Limited concern
Lower concern for a MADE SAFE certified shampoo avoiding fluorinated ingredients.
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Puracy
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1,4-dioxane (contaminant in ethoxylated surfactants)
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Formaldehyde / VOCs
Limited concern
Lower concern for a liquid shampoo with minimal PFAS risk in this category.
⚠Risky category by default
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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.