PUL-eez tell me it’s safe! A look at the safety of PUL fabric in Cloth Diapers.


On Twitter tonight (it’s Wednesday) there is a chat called EcoWed.  Folks on Twitter chime in on topics that are eco-related and also often health related.  One of the frequent discussions is around the safety of plastics.

Recently a customer emailed about a concern with the safety of using Polyurethane Laminate (PUL) covers for her newborn.  She had done some preliminary research that left her with some questions.

Let’s take a look at PUL.  PUL is a very common fabric used in the diaper industry.  It is used in many other industries as well.  For the purpose of the following information, we are only looking at PUL specifically manufactured for cloth diapering.

PUL is used for the outer layer of diapers or as the fabric for diaper covers and functions to keep the wetness in while allowing airflow to reach the baby’s skin.  It is very durable, even under the rigorous washing conditions associated with washing cloth diapers.

Thanks to Shirley of Bummis, we have some good (and reassuring) information to share with you.  Bummis is the manufacturer of the Canadian made and gold standard Super Whisper Wrap and Super Brite Diaper covers.

Firstly, all of the fabrics used in these diaper covers meets or exceeds US Government CPSIA standards indicating that there are no diisocyanates present in the polyurethane lamination.  Diisocyanates are a respiratory hazard for which inhalation and dermal contact should be avoided.  Other potential toxins that are standard for CPSIA testing include hydrogen cyanide, pthalates, formaldehyde or lead.  While these are not expected to be present at any level in PUL testing confirmed that the levels of these potential toxins were zero.

On the making of PUL – PUL is formed by reacting polyol with diisocyanates in the presence of suitable catalysts and additives.  This makes the thermoplastic polyurethane (TPU) from initial stages of the polymerization.  This process is completed in a factory within a controlled environment.  Once the polymer is made, these initial substances cease to exist as they were and have formed another compound known as TPU.

The newly created TPU is an inert material.

The Material Saftey Data Sheet for TPU states that it only releases harmful chemicals above 428F degrees.  This is true for all plastics.  If any TPU was heated to such a high melting point, they could release toxic fumes but this is not the case in a stable product with regular use.

TPU is used on open wound dressings as the waterproof film that stops fluids from seeping out.  One of the reasons TPU is used in this application is that it is not an irritant.  Beyond dressings, TPU is used in many medical invasive applications approved by the US FDA.

So with that all said, are PUL diaper covers safe for your little one?  Yes, with regular use and care, they are comprised of inert substances that will not expose your child to potentially toxic fumes or chemicals.

8 thoughts on “PUL-eez tell me it’s safe! A look at the safety of PUL fabric in Cloth Diapers.

  1. Irene

    I’ve done some reading about PUL, and have a few issues myself.

    1)There are reports of PUL irritating baby’s skin. At the end of the day, it’s still a plastic, and thus a synthetic material. Some babies will react to this because it’s synthetic. Fortunately, my little guy doesn’t react to it, as 3/4 of my stash has PUL.

    2) I haven’t seen studies done, but there are claims that PUL isn’t as breathable as natural fibres like wool and hemp. Is this true?

    3) PUL is still a plastic, and it will eventually have a end of life, like everything else. It will end up in the landfill. What are consequences of having it biodegrade over time, because it is a synthetic material, will it leave a toxic footprint behind, and how long will it take to biodegrade? This is the one thing about PUL that bugs me the most, it’s not as green as it is touted. Greener than disposables, because it is resued many time, but not greener in the bigger picture.

    I would like to see a good alternative to PUL that we can recycle or can be biodegrade safely.

    1. Karen Post author

      Hi Irene,

      Great questions and considerations. I’m wondering if you can send me the references for the reports you’ve seen about PUL irritating babies’ skin. I’d love to look into it. Agreed, some babies are simply more sensitive and anything synthetic will cause a reaction.

      On a scale of not breathable to breathable, natural fibers are on the extreme end of breathable and PUL is in the middle. It is breathable but natural fibers like wool are far more superior in their breathability.

      I will look more into your question about the biodegradability of PUL. Given the information presented in this piece, there will only be a risk of PUL releasing noxious substances when it is heated beyond 428F.

      Agreed that it is a greener option than disposables and for the reason that they are reusable. What sits better with you – using 6-12 diaper covers for the duration of your diapering time and then reusing them for a second child (sibling or passing them along) or using disposables (and the plastics associated) for both of these children at 7200 diapers per child. The eco-footprint is astonishingly different for the waste created.

      Agreed – an alternative would be great. I’m sure it will come along soon; there are lots of folks doing R&D in the cloth diapering industry.

  2. kristen conn

    thanks for this great information! i have been concerned about this issue and glad to read these are still a safe option. (Assuming what we are using (Fuzzi Bunz) meets the same requirements!)

    1. Karen Post author

      Hi Kristen,

      Thanks for reading. All PUL fabrics from Fuzzi Bunz will meet or exceed CPSIA standards as this is an USA based company. Let us know if you have any other questions.

  3. Lisa Hehr

    I am looking for the link that will show the chemical breakdown of pul and its safety etc…I found it once but cant find it again 🙁 Any chance you have it handy?

  4. Michaela

    Hi Karen,
    would the same testing apply to Blueberry and Thirstie covers. I’ve contacted both they haven’t mentioned anything about diisocyanates, but wrote : Our products do not contain or emit any Volatile Organic Compounds, PVC, or latex and are phthalates and lead free. Formaldehyde?
    Thanx for great article. Michaela 🙂


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