Is a baby sleeping bag neck opening too big under EN 16781?

What neck size does EN 16781 actually set?

UL's November 2025 briefing for the British Retail Consortium says one of the main hazards is a child slipping through the neck opening so that fabric covers the head. To limit that, EN 16781 specifies a minimum and maximum neck-opening circumference in relation to the child's height, for three development sizes.

A neck that is too large lets the child slide through. A neck that is too small is also out of range — the clause is a band, not 'as tight as possible'. The measurement is a lab test under a set force, not a tape you pull hard around a crumpled neckline in a shop.

What did the 2025 Marks & Spencer recall say about neck size?

On 11 November 2025 OPSS published product recall 2511-0077 for the Marks & Spencer Stripe 2.5 Tog Baby Sleepbag (product code T92/4648S, barcodes 9927667, 9930230, 9944855; sizes 0–6 months, 6–18 months and 18–36 months).

The hazard line is: the neck measurement does not fall within the parameters specified in BS EN 16781, presenting a risk of strangulation. The product was recalled from end users. M&S directed owners to its recall page and customer services. That is a high-street example of the same clause marketplace investigations keep hitting.

Official records show 2511-0077 is a neck-measurement miss against BS EN 16781, not a hood or TOG story. If you hold that product code, follow the notice: stop using it and use the M&S contact route. MayTally does not process the recall.

What have Which? tests found on neck openings?

Which? lab tests in 2020, run against extracts of BS EN 16781:2018, found neck openings they judged too wide on both marketplace and high-street bags. Those figures are investigative measurements, not a full copy of the standard table.

Which? also found missing warnings about fastening the neck and arm openings. The standard is not only a centimetre band — it expects instructions that tell you to fasten those openings before sleep.

How do I check the neck on a bag I am buying or already own?

1. 1
   Read the size line, not the age on the hanger The Lullaby Trust says most baby sleeping bags are fitted by weight, not age, and should be well fitted around the neck and shoulders so the baby cannot wriggle down. NHS safer-sleep advice says the bag should fit well around the shoulders so the head cannot slip into the bag.
2. 2
   Look at the baby, not only the tape On the child who will wear it, the neckline should sit on the shoulders. If you can pull the neckline up over the mouth, or slide the bag up the torso, the opening is too big for that child even if a label looks plausible.
3. 3
   Match height if the label gives it If the maker prints a height band, the only public EN 16781 example UL quotes is 50–65 cm → 28–32 cm circumference under Clause 4.1.2.2. Do not invent other official bands from a shop tape measure.
4. 4
   Search the model on GOV.UK Put the brand, product code or barcode into Product Safety Alerts, Reports and Recalls. 2511-0077 shows a neck miss can appear on a labelled high-street 2.5 tog bag, not only on a marketplace cocoon.

A home tape measure is not Clause 4.1.2.2. Use it as a sense-check (roughly 28–32 cm for the smallest height band UL quotes), then rely on the labelled weight or height range and how the bag sits on your baby.

Can a neck opening be too small as well as too big?

Yes. UL describes both a minimum and a maximum. The minimum exists so the opening is large enough for the named height when tested. A neck that cuts in, leaves red marks, or cannot be fastened without stretching the fabric is a fit problem — stop and change size or product rather than forcing poppers.

The revision UL describes (not yet the current published EN 16781:2018) would add a fourth height range and a different neck test. Until a new dated standard is published and adopted as BS EN, the 2018 code and the current label are what shops and OPSS are citing.

In shortEN 16781 bounds the neck by height so the child cannot slip through. The only full band UL quotes in public is 28–32 cm for 50–65 cm. The 2025 M&S recall was a neck measurement outside the standard. Fit the bag by the maker's weight (or height) line and by how it sits on the shoulders.