Is the TOG on a sleeping bag label lab tested?

Is the printed TOG a lab result for this bag?

The digit on the hang-tag is the declared thermal resistance — the figure EN 16781:2018 requires in the instructions for use. It is the maker's statement of how insulating they say the bag is. It is not, by itself, a certificate that the unit in your airing cupboard sat on a hotplate last week.

The Lullaby Trust defines TOG as a measure of insulation used for sleeping bags and blankets: the higher the number, the warmer the product. That definition does not say every production batch is re-measured. Parents often treat the print as a fact. Lab work and one supermarket recall show the print can be wrong.

How does EN 16781 test thermal resistance?

Bolton Consultancy, a UK textile-compliance practice, lists the EN 16781 thermal-resistance method as an adaptation of ISO 5085-1. The standard also carries an informative annex on thermal measurements. UL's BRC briefing says sleep bags undergo thorough testing to verify thermal resistance and that EN 16781 requires a maximum of 0.40 m²·K/W (4.0 TOG).

That ceiling is a cap, not a target. A bag labelled 0.5 TOG that measures far warmer can still sit under 4.0 TOG and be the wrong product for a warm room. SGS's 2020 note says insulation has to be chosen to suit the environment and that overheating is a recognised factor in sudden infant death.

What did Which? and the Argos recall show?

Which? (7 September 2020) ran lab tests on 15 bags. Inaccurate TOG ratings that could lead to a baby overheating were one of the named failure types. One AliExpress 'newborn' bag measured 4.2 TOG when the standard's upper figure should not exceed 4. A Wish fox-themed bag 'exceeded the upper tog level by 26%'. Those are measured warmth versus the rules, not a parent guessing from the fabric.

Separately, Argos and Sainsbury's recalled two Tu baby sleep bags in October 2019 because the insulation exceeded the specified rating. PlayPennies recorded the bags as labelled 0.5 to 1 TOG. Official local-authority copies of the notice name style numbers 134877764 and 134878142. A Tu spokesperson said the design 'may exceed its tog rating' and asked customers to stop using the product and return it. The notice offered a refund of £14 without proof of purchase.

Official records show those two Argos style numbers were withdrawn because labelled insulation did not match the bag. A later Which? fail on a different brand is a lab result, not the same notice. Search the model on GOV.UK if you still hold a coded bag.

How should I treat a TOG already on my label?

1. 1
   Copy the claim, not the marketing name Write the printed TOG, the size, and any style or batch code from the sewn-in label. Recall notices use those codes, not 'the floral one'.
2. 2
   Search official lists for that code Use the GOV.UK Product Safety Alerts, Reports and Recalls search. The 2019 Argos notice is the template: insulation higher than specified, stop using, return route named.
3. 3
   Do not stack bags to 'add TOG' The Lullaby Trust says dressing a baby in two 1.0 TOG bags does not make 2.0 TOG — trapped air between layers increases warmth. That is a charity line about layering, not a lab pass.
4. 4
   Feel the chest or the back of the neck The Lullaby Trust's check is skin on the chest or neck, not hands and feet. A printed 1.0 TOG does not replace that check if the room is hot or the bag feels bulky for the claim.

Does a 4.0 TOG ceiling mean a warmer bag is better?

No. The 4.0 TOG figure in the UL summary is a maximum thermal resistance for a children's sleep bag under EN 16781. It exists because overheating is one of the hazards the standard is written to limit. A bag that measures 4.2 TOG failed Which?'s reading of that cap. A bag that honestly measures 2.5 TOG can still be too warm for a 22 °C room.

The Lullaby Trust does not publish a room-temperature-to-TOG chart. It asks families to follow the manufacturer's tog guide and to check the baby. NHS Start for Life still prints commercial bands (2.5 / 1.0 / 0.5 TOG) on its safer-sleep page. Those bands are clothing advice, not evidence your hang-tag was measured.

How is this different from a room-temperature chart?

A room-temperature chart tells you which claimed TOG a brand wants you to pick for 16 °C or 24 °C. This page asks a prior question: was that claim lab-tested, and has anyone found it wrong? Which? and the 2019 Argos / Sainsbury's notice are about mismatch, not about whether 2.5 TOG is the 'right' winter number.

In shortIn short: treat the printed TOG as a declared claim that EN 16781 expects a lab method to support. Which? measured bags that were warmer than the rules or the print. Argos recalled two styles for the same kind of mismatch. Recheck the code on GOV.UK; do not add a second bag to 'make up' TOG.