Q: Exact dimensions: what is the precise thickness to the nearest 0.1" (the listing states '<6"') and the exact width/length tolerance so I can confirm a snug fit in older or non-standard cribs?

Our listing shows Dimensions 27.5" W × 52" L × <6" H and a 6" recycled fiber core, but some retailer/spec sheets list the finished mattress height as 5.0" — published specs are inconsistent, so we cannot state a single thickness to the nearest 0.1" with certainty. For fit tolerance: the mattress is sold as a standard full‑size (27.5" × 52") and the CPSC minimum mattress size is 27 1/4" × 51 1/4" with a maximum thickness of 6"; check your crib’s internal measurements and make sure there’s no more than a two‑finger gap between mattress and crib side to confirm a snug/safe fit.

Question 1

What is the Standard Size of a Crib Mattress?

Accepted Answer

The Consumer Products Safety Commission (CPSC) requires all full-size baby crib mattresses to be at least 27 and ¼ inches in width by 51 and ¼ inches in length, with a maximum thickness of six inches.

Question 2

What is the Standard Size of a Baby Crib?

Accepted Answer

The CPSC requires that full-size baby cribs have a standard width of 28 inches and a standard height of 52 and ⅜ inches (with a “pull or minus factor” of ⅝ inches). Because of this variation, check the recommended mattress size on the crib’s box or assembly instructions.

Question 3

How Can I Tell if a Crib Mattress Fits in my Crib?

Accepted Answer

A crib mattress should fit very snugly in the crib — no more than two fingers of space should exist between the mattress and the crib frame. A mattress that is too small can be a suffocation and entrapment hazard.

Question 4

How Firm Should a Crib Mattress Be?

Accepted Answer

Crib mattresses should be firm. Soft surfaces can pose a suffocation hazard and increase the risk of SIDS. Test firmness by pressing the center and edges — the mattress should snap back immediately when pressure is released.

Question 5

What is the mattress firmness expressed as an industry measure (ILD) or on a 1–10 scale for the Delta Children Twinkle Stars 6" mattress?

Accepted Answer

This Twinkle Stars 6" mattress is described as a firm, dual-sided 6" fiber-core crib/toddler mattress (suitable for newborns and toddlers) but the manufacturer does not publish an ILD value or a 1–10 firmness rating for this model. You can see the product’s firm construction and 6" fiber-core spec on the Delta Children product page.

Question 6

The listing says it meets flammability testing and contains no toxic fire retardants — what specific fire-barrier material or construction is used to meet flammability standards?

Accepted Answer

We confirm this mattress meets required flammability testing and contains no added toxic fire retardants, but Delta Children’s public product information does not specify a named fire‑barrier material or exact construction used to meet those standards. Independent reporting found Delta did not disclose full mattress components, so a specific barrier (wool, rayon, woven fire sock, etc.) is not listed in available documentation; the product is GREENGUARD Gold certified and tested to CPSC/ASTM requirements.

Question 7

Is the outer cover a waterproof vinyl shell or a knit cover with a waterproof backing (the product description mentions both)? If it is removable, can the cover be machine washed and what are the care instructions?

Accepted Answer

This mattress has a soft knit outer cover with a waterproof layer/backing on both sides — it is not described as a full vinyl shell on the Delta product page. The product page for this 6" recycled-fiber Twinkle Stars mattress does not list the cover as removable, so clean the waterproof backing with a damp cloth or spot-clean; do not expect the mattress cover to be machine-washable. If you need a Twinkle Stars model with a fully removable, machine-washable knit cover, Delta also sells a “Breathable” Twinkle Stars variant that explicitly lists a removable, machine-washable cover.

Question 8

Does the waterproof material (backing or vinyl) contain PVC or other plastics of concern, and which phthalates (if any) were specifically tested for in the GREENGUARD/ compliance testing?

Accepted Answer

This mattress has a durable, waterproof vinyl cover and is GREENGUARD Gold certified; Delta states its crib mattresses are non‑toxic and tested to meet/exceed CPSIA/phthalate requirements. [1] We do not publish the mattress’s exact polymer formulation (so we can’t confirm whether the vinyl backing contains PVC) or a public lab report listing the specific phthalates tested for this SKU; the applicable U.S. rules and testing programs used for children’s sleep products restrict and test for a set of phthalates including DEHP, DBP, BBP and the additional phthalates later restricted by the CPSC (e.g., DINP, DIBP, DPENP, DHEXP, DCHP). [2]

Sources

Delta Children product page (product_features) and CPSC phthalate rule/news release (CPSIA/CPSC testing requirements)

Question 9

Has the mattress been independently tested for breathability or heat retention (e.g., airflow rate, thermal testing) compared with a standard vinyl-only crib mattress, to support the claim of the 3D airflow knit cover?

Accepted Answer

We are not aware of any published, independent laboratory tests (airflow-rate or thermal/heat‑retention measurements) that directly compare this Twinkle Stars 3D‑knit cover to a standard vinyl‑only crib mattress. The Delta Children product page describes the knit cover as a “three‑dimensional structure that allows air to flow,” but that is a product feature statement, not a third‑party airflow/thermal test. Note that GREENGUARD Gold refers to low chemical emissions, not measured breathability or heat‑transfer performance, and available third‑party reviews report informal breathability checks rather than formal lab testing.

Question 10

Exact dimensions: what is the precise thickness to the nearest 0.1" (the listing states '<6"') and the exact width/length tolerance so I can confirm a snug fit in older or non-standard cribs?

Accepted Answer

Our listing shows Dimensions 27.5" W × 52" L × <6" H and a 6" recycled fiber core, but some retailer/spec sheets list the finished mattress height as 5.0" — published specs are inconsistent, so we cannot state a single thickness to the nearest 0.1" with certainty. For fit tolerance: the mattress is sold as a standard full‑size (27.5" × 52") and the CPSC minimum mattress size is 27 1/4" × 51 1/4" with a maximum thickness of 6"; check your crib’s internal measurements and make sure there’s no more than a two‑finger gap between mattress and crib side to confirm a snug/safe fit.

Question 11

Will adding a standard thin mattress protector or fitted sheet designed for crib mattresses change the mattress firmness enough to affect safety recommendations (i.e., is using a protector/sheet recommended or discouraged)?

Accepted Answer

This mattress is firm and already has a waterproof layer on both sides, so a thin protector isn’t required for waterproofing or firmness. If you choose to use one, pick a thin, crib-specific protector that does not add cushioning and keep a tight-fitting crib sheet over it — avoid padded toppers or loose covers because leading safe-sleep guidance recommends a firm sleep surface with only a fitted sheet to reduce SIDS/suffocation risk.

Delta Children Twinkle Stars Dual-Sided 6" Recycled Fiber Core Crib & Toddler Mattress, Waterproof, Greenguard Gold certified

Specifications

Image Analysis

Brand PDP Lookup

Documents & Data

Customer Reviews

BEST MATTRESS EVER

Worth every buck

Such a great quality mattress