Your Guide to TCF and ECF Diapers: What Parents Should Know

We know how much thought and care goes into every product you choose for your baby, and we take that responsibility seriously. 

Since launching our new (and improved!) Thrive Market Ultra Soft & Absorbent Diapers, some members have reached out with thoughtful questions about our transition from totally chlorine free (TCF) to elemental chlorine free (ECF) pulp. The shift was driven by the realities of the global pulp supply, and we only made the decision following extensive research and testing to ensure that our diapers would continue to meet the highest standards for safety and environmental responsibility. 

There’s a lot of information—and misinformation—online about TCF, ECF, and chlorine-related terminology, and it’s entirely understandable to want clarity. We’d like to break down the differences so you can feel confident and supported in your choices.

What’s the difference between totally chlorine free (TCF) and elemental chlorine free (ECF) diapers?

Chlorine appears during the “bleaching” step in diaper manufacturing; this isn’t about whitening diapers for appearance, but rather to purify the wood pulp that gives diapers their absorbency. This process removes natural lignin (the part of wood that gives it a brownish color) so the pulp becomes clean, soft, and able to absorb moisture efficiently.

There are two common methods for bleaching the wood pulp: totally chlorine free (TCF) and elemental chlorine free (ECF). Here are the differences: 

• TCF, or totally chlorine free, methods rely on oxygen-based agents such as hydrogen peroxide or ozone to whiten the pulp in diapers. These methods are designed to be gentle and effective without creating dioxins (the harmful byproducts that were once associated with older forms of chlorine bleaching decades ago). Because TCF uses only oxygen-based compounds, it’s often perceived as the “cleanest” option, and it was originally developed as a way to ensure that pulp bleaching could be done without introducing potentially harmful contaminants into the environment.
• ECF, or elemental chlorine free, processing takes a different approach but reaches the same important outcome. Instead of using oxygen-based agents (like those used in TCF) or harmful elemental chlorine gas (an obsolete bleaching method), ECF uses chlorine dioxide, which sounds similar to elemental chlorine but behaves very differently on a chemical level. In fact, modern ECF methods were specifically developed to virtually eliminate dioxin formation produced with traditional bleaching methods while also improving efficiency and environmental impact from TCF.

Why does the word “chlorine” show up at all?

It’s a question we hear often, and it makes sense! The word alone can feel alarming.

Here’s the important distinction:

• Elemental chlorine (Cl₂) processing is the outdated method that left toxic dioxin residue behind in the diaper (it would remain attached to the wood fibers in the diaper’s absorbent core) and released persistent pollutants such as dioxins into the environment. For this reason, our diapers are elemental chlorine free.
• Chlorine dioxide (ClO₂) is a different compound entirely. It drastically reduces dioxin formation to levels that are negligible in the final product and is considered safe for pulp bleaching worldwide.

Are Thrive Market Diapers still safe for my baby?

Yes, absolutely. What often gets lost in online conversations is that both TCF and modern ECF methods are designed to prevent dioxins; they simply use different tools to get there. Regulators and environmental agencies worldwide consider both approaches safe, and both are widely used in products designed for sensitive uses (like baby diapers, feminine care products, and even food-grade packaging).

Our diapers also continue to meet these incredibly high safety and quality standards:

• No phthalates, parabens, fragrances, or lotions 
• OEKO-TEX® STANDARD 100 certified (tested for 1,000+ harmful substances)
• Hypoallergenic and dermatologist-tested

Are ECF diapers environmentally responsible?

Yes—and in fact, the debate between TCF and ECF is largely environmental, not a health issue. Today’s ECF processes virtually eliminate dioxins, are more energy-efficient, and are aligned with the standards environmental regulators recommend. TCF does not emit dioxins but typically requires more energy and results in a lower pulp yield. Over time, that additional energy use lessens many of its environmental advantages.

There is very limited TCF pulp available worldwide, and most of it is now directed toward other industries, which means it’s not reliably accessible in the volumes required to produce diapers. TCF pulp is also significantly more expensive, and the scarcity makes it difficult to maintain a consistent, dependable supply. 

Why did Thrive Market diapers switch from TCF to ECF?

We made this shift with great care, focusing on what’s safe for babies and what’s best for the environment. Here are our main reasons for the switch:

1. The safety stays the same

The modern ECF method drastically reduces dioxins, and it’s widely recognized by environmental and health regulators as safe.

2. Maintains a consistent supply chain

The global supply of TCF diaper-grade pulp is extremely limited and often prioritized for other industries, including medical applications. Continuing to rely on it would have risked both supply consistency and cost stability. Transitioning to ECF supports our ability to deliver a safe, high-performing, and cost-efficient diaper without compromising reliability for our members.

3. Better environmental efficiency

While the TCF method was developed with the goal of reducing dioxins, it often requires more energy and produces less pulp, which can offset its benefits. Today’s ECF methods virtually eliminate dioxins, too, but with greater efficiency and lower impact.

4. Aligns with trusted industry standards

Most high-quality diaper brands now use ECF. Making the switch allows us to continue providing high-performing diapers that meet your needs without sacrificing safety or quality. 

What else changed about the new Thrive Market diapers?

We took this refresh as an opportunity to make our diapers even better for babies and parents. The updates include:

• Up to 12-hour protection to keep baby’s skin dry
• More consistent, true-to-size fit that’s softer and stretchier
• Even gentler feel made with breathable, plant-based materials
• OEKO-TEX® and FSC certifications for complete peace of mind

And the features you already loved? They’re still part of every pack:

• Hypoallergenic and dermatologist-tested
• Made without fragrance, parabens, phthalates, lotions, or natural latex
• Easy-to-read wetness indicator

Conscious Care For You and Your Family  

We know parents put thought and research into every diaper decision, and we want you to feel fully supported in that process. Our goal is to support you with clarity and care as you make the choices that feel right for your family. Whether that means choosing our Thrive Market diapers or another trusted brand, we respect your decision.

If you still prefer to use TCF diapers for your family, we’d love for you to consider our remaining stock of Thrive Market TCF diapers, or one of the TCF brands available at Thrive Market, such as Bambo Nature.

Your trust means everything to us, and we’re committed to showing up with honesty, transparency, and care every step of the way. If you have any questions about our diapers or need help choosing the right size, feel free to contact us at help@thrivemarket.com.