Response to Which?

Here is our full response to the Which? article.

If you’ve read the recent Which? article we understand you will be disappointed. We are too. We want to assure you that our bamboo toilet paper is made only of bamboo. 

We provided Which? with so much information that verifies our bamboo - it is impossible for us to understand how a well-respected and responsible publication could have published such a misleading and inaccurate article.

Prior to publication Which? was provided with comprehensive information about our supply chain and the FSC's external audit trail. We also clearly provided the reasons why Naked Sprout does not use the TAPPI T 401 test to analyse our finished products, or to verify our supply chain.


  1. Naked Sprout bamboo product is made from bamboo only. Our supply chain verification proves this.
  2. Our entire supply chain is FSC certified. FSC is the most credible supply chain organisation worldwide; as Which? themselves acknowledge. We have had confirmation from our FSC certification holder that there have been no issues identified with any of our pulp suppliers.
  3. At Naked Sprout, we don’t use the TAPPI T 401 test, because it’s not suited to our unbleached bamboo products. The TAPPI T 401 test stains the fibres of the paper, which change colour depending on the raw materials used. A human then looks through a microscope to differentiate between the colours. There are similarities in results between all kinds of ligneous fibre and bamboo, and the analysis is hindered by the degree and type of cook (e.g. whether the paper is bleached or unbleached). The body behind the TAPPI T 401 test themselves acknowledge that “erroneous identification and improper separation can greatly influence the results”.
  4. Which? have refused to share a copy of the test results with us. Meaning we are unable to interrogate the results and how they came to their conclusion. 


In their April Edition, Which? published a review of sustainable toilet rolls. They accuse us of having potential issues within our supply chain. Prior to publication Which? contacted us and our reply gave a full description and comprehensive audit trail of our supply chain. 

We were surprised their final article omitted the following points:

  • All our bamboo pulp and products are FSC certified (we provided the certificates!).
  • Our end products can be traced back to each raw material purchase (we provided end to end data!).
  • The TAPPI T 401 test is a subjective analysis which acknowledges "erroneous identification" of fibres is a problem and not suited to our unbleached bamboo product.
  • Due to fossil fuel free manufacturing, Naked Sprout products are more sustainable than other eco brands (who stop at the raw material).

We speak with everyone involved in our supply chain from the bamboo pulp suppliers themselves to the FSC who externally audit and monitor our entire chain. Our supply chain is small to allow for detailed, accurate monitoring. 

We provided Which? with our full audit trail evidencing our bamboo pulp from source to production. Also inviting them to visit our factory. Our audit trail included a year’s worth of supply chain data - to prove the only raw material used to manufacture our bamboo toilet roll is bamboo. For reasons we do not understand, Which? confirmed they have not assessed this data.

We requested a copy of the Which? TAPPI T 401 test results to confirm it was a Naked Sprout roll tested and one of our bamboo rolls rather than recycled. Which? have refused to share a copy of the test with us.

We explained our reasons to Which? for not using the TAPPI T 401 test to anaylse our finished product to verify our supply chain. Clear disclaimers in the test documentation and our own research led us to the firm conclusion that the test would not provide a robust or reliable form of audit. Particularly for an unbleached bamboo product.

Here is our response in full.

1. Our bamboo

Which? did not assess our supply chain or our supply chain evidence. Therefore, the conclusion that our sustainable products do not stand up to scrutiny is wrong and had they considered the evidence provided to them, an impossible conclusion for them to reach.

All four of our bamboo suppliers are based in an area widely known for vast natural bamboo forests. Our main supplier owns one million acres of bamboo forest! The FSC certify they are not sending eucalyptus and softwood to us. They send the bamboo they grow and harvest. There is no advantage to supplying materials sourced elsewhere at a greater cost.

It’s not just geography and cost that makes this so unlikely. The annual FSC auditing of our suppliers means there is a robust chain of custody for all certificate holders. These controls prevent cross contamination.

2. FSC certification

For enhanced monitoring, our bamboo suppliers are certified by the Forest Stewardship Council (FSC). 

The FSC is an international organisation that provides the most respected and widely used certification system for responsible forestry. It has carried out independent auditing of the commercial forestry projects where our bamboo grows and is harvested. There are controls in place to prevent the cross-contamination of different species. Our suppliers undergo in-person audits to make sure their weight in, weight out system is scrutinised. We have had confirmation from the FSC there have been no issues identified with any of our pulp suppliers. 

Our bamboo pulp is purchased by weight. The weight is included on the invoice they provide. Once we receive the pulp at our B Corp certified factory the weight is checked again. This is recorded using specialist software for each batch of bamboo toilet roll we make. We can trace every pallet, box and roll back to the batch of pulp and the FSC-certified forest where it grew using our Traceability Log. In effect doubling the supply chain monitoring required for our FSC certification. This Log gives us full visibility of our production process. We sent Which? a copy proving there have been no irregularities in our supply chain. Which? have chosen not to engage with this evidence. 

The FSC audits our suppliers to ensure the weight of bamboo harvested and pulped matches the weight of bamboo sold to customers. In 2022 the FSC introduced a transaction verification loop system. This takes the verification of bamboo very seriously (more information found here). We keep our supply chain deliberately small in order to make sure our bamboo is easily traceable. We only use four suppliers and one manufacturer. Additionally, FSC audit and certify Naked Sprout and our manufacturer according to their chain of custody requirements.

In the article, Which? states that “bamboo’s impressively fast growth when combined with FSC certification means that it can be considered as a more sustainable option than virgin timber.” In a separate article from July 2022 Olivia Howes, the same journalist, recommended the FSC as “the best option”. This article explicitly assures readers that the FSC provides a trustworthy certification system.

Which? does not mention that all our products are FSC certified. Possibly because of the above contradiction. In one article they are advising consumers to trust the FSC but in another they are using an unsuitable test to disprove the FSC supply chain of toilet roll. Which? has not provided any alternative certifications that might be used. They have accused 3 FSC certified brands of low bamboo content but as far as we are aware have not approached the FSC for comment.

We stand by the FSC’s certification system, particularly given the disclaimers and limitations provided in the TAPPI T 401 test documentation (see further below), together with our own research about the suitability of this test. 

We believe the Which? TAPPI T 401 findings are a result of misidentification or “erroneous identification” as expressly highlighted in the TAPPI T 401 test documentation. Not a failure of the FSC’s internationally recognised and widely respected system; a failure which would have wide-ranging implications for the paper and timber industry as a whole and one that Which? has been careful to avoid. 

3. TAPPI T 401 test method

Which? have based their review on the results of a TAPPI T 401 assessment. The results showed 96% eucalyptus and softwood and 4% 'unidentified grass fibre'. This is beyond baffling. 

The Which? article assumes the TAPPI T 401 test is an accurate way to assess bamboo toilet roll raw materials. As explained - it is not. Despite repeatedly highlighting the limitations and disclaimers in the TAPPI T 401’s own test documentation Which? affirmed that their review is solely focused on the results of this test. They have not assessed the supply chains of the relevant brands.

The Paper Industries Technical Association guidance does not include the TAPPI T 401 test in its guide to commonly used test methods. Which? states this is an industry standard test. We are unsure how they state this with any certainty.

The major problem with the Which? article is they present the TAPPI T 401 test and results as a matter of fact without any acknowledgement of the test’s limitations and disclaimers in circumstances where the Paper Industries Technical Association guidance does not recommend it. This means Which? has described the TAPPI T 401 test as the industry standard when it is not.

We previously completed research on the suitability and accuracy of this test. Seeking out scientific reviews and independent scientific advice. We have not been influenced by competitors or laboratories selling a particular testing option. 

The Naked Sprout results of the Which? TAPPI T 401 test correlates with our own research that it is unreliable and inaccurate. We previously conducted TAPPI T 401 tests on competitors' products and all showed less than 100% bamboo.

The test method document details the procedures used for TAPPI T 401 testing. It explains how the colours shown when using staining differ depending on the presence of raw materials and the process used. It is important to point out that there are similarities in results between unbleached pulps of all kinds of ligneous fibre and bamboo. This identification is then subjectively assessed by a human.

The documentation of the TAPPI T 401 test expressly highlights the potential for misidentification, stressing that:

There is considerable variation in the precision to be expected in fiber analysis. The ability to differentiate between colors which are only slightly different is very important so that no matter how well the samples are taken, slides prepared, and related statistics calculated, erroneous identification and improper separation can greatly influence the results.” 

The TAPPI T 401 method is based on observations using a microscope and is a subjective analysis hindered by morphology differences present in different samples of bamboo as well as the degree and type of cook (e.g. unbleached / bleached). This is expressly stated in the TAPPI T 401 “Fibre Analysis of Paper and Paperboard” test method document, published in 2020. As the limitation states “no matter how well the samples are taken, slides prepared … erroneous identification and improper separation can greatly influence the results”.

Various studies state bamboo fibres and morphology can vary greatly depending on the species, geography and seasonality - and can display characteristics similar to both hardwood and softwood fibres. There are more than 1650 known species of bamboo.

Based on the above, TAPPI T 401 method is subjective and can neither be relied on to determine composition nor reliably extrapolated beyond the sample taken when used on unbleached bamboo products.

We believe the results described by Which? support this argument. The simplest explanation for why the test was not able to positively identify any bamboo, despite our certified audit trail, the FSC’s checks and the location of our suppliers is because the test is inaccurate and not suited to our unbleached bamboo products. Remember - Which? says you should rely on FSC certified products like ours. 

The definition of “Sustainability”  

The definition of “sustainable” employed in the Which? article is focused on raw materials. Many other eco brands in our sector limit their efforts to using bamboo and avoiding plastic. We go far beyond this. We manufacture without using any fossil fuels to power our processes, meaning that our total CO2e emissions are at least 50% lower than other eco rolls, and recycled rolls made in the UK. 

We will keep working to find the most sustainable processes possible. In the last 12 months alone we have:

  • Developed and launched unbleached recycled rolls made from recycled cardboard and kraft paper used for packing and delivery. An underused source of raw materials.
  • Reduced the inner core of our rolls and revised our packaging so our boxes are now 44% smaller, increasing the amount we can fit on a pallet. Reducing our freight carbon footprint.
  • Started to transport our rolls from our B Corp, living wage accredited factory in Spain to the UK via electrified rail. This further reduces the impact of transporting our products. 

For Naked Sprout sustainability isn’t a branding exercise. We are contributing to a necessary shift away from manufacturing using fossil fuels. In 2024 we will be the first toilet roll company to introduce full climate labelling to our boxes.

We are extremely open about the way we make our products. In the last year we have been delighted to share more information about our processes with The Ethical Consumer. They placed us at the top of their ranking for ethical and sustainably made toilet rolls. We have also completed two independent Life Cycle Assessments of our products and processes (compliant with ​​ISO14067). 

Making products in a way that is sustainable means taking into account every part of the supply chain and manufacturing process. We believe that full transparency is necessary. We don’t have anything to hide, and we trust our customers and supporters will see this. 

If you have read this far, thank you for hearing us out. We would like to assure you that we will continue to make toilet rolls using FSC certified bamboo and recycled packing materials. We will keep pushing ourselves to go far beyond simplified definitions of sustainability to drive genuine change in our industry.

Our invitation to Which? still stands to visit our factory and see our environmental initiatives. As well as how our product is manufactured. Any other interested publication is also welcome to contact us about this and to view our full Traceability Log.

Tom and Leila, Founders