Last month, we revealed our new scale of animal-free testing. As we’ve discussed, in vitro testing doesn’t automatically mean animal-product-free and the scale is intended to help organisations distinguish between the different levels of animal products used, to make better informed decisions about the testing approach you want to follow. For instance, many tests still use foetal bovine serum which involves a degree of animal suffering whilst others replace this with more ethically-sourced human serum.

XCellR8 scale of animal-free testing

In this article, we set out to share how we use the scale at XCellR8 to inform our decision making and the way we conduct our work in the lab:

  1. Cell lines should be adapted to grow in media that does not contain animal serum. Ideally media should be wholly chemically-defined but, if that is not possible, then ethically-obtained human serum should be used.
  2. Only human-derived cell lines, rather than animal cell lines, should be used. From a scientific perspective, for testing the toxicity of chemicals to humans, the use of human-derived cell lines is essential.
  3. Protein-based components (e.g. antibodies, extracellular matrix proteins, media supplements etc) should all be derived from recombinant or human sources wherever possible.
  4. Tissue extracts (eg liver extracts used to incorporate metabolic capacity into genotoxicity tests) should all be from human sources.
  5. The generation of test components, such as reconstructed human tissues, should avoid the routine use of animal-derived elements in the production process wherever possible.
  6. Our supply chain needs to be both monitored to ensure that we source animal-product-free materials when we set up new tests, and regularly audited to maintain compliance.
  7. Tests should always be conducted in a way that achieves the highest possible level of animal-product-free compliance (Levels 1-7 as described in the scale).

What is the answer where animal-free tests don’t exist?

What if completely animal-free testing is not possible in some instances? This is a challenging dilemma; certain tests must be conducted in order to meet safety regulations, and yet there are not always wholly animal-free methods available to perform these tests.

One example of this deficit is the traditional acute toxicity ‘six-pack’ of tests which still requires animal tests for some categories. The six pack comprises tests for acute toxicity via oral, skin, and inhalation exposure, as well as through eye and skin irritation and skin sensitivity. The OECD test guidelines have been updated to apply 3Rs principles to the acute toxicity tests, thereby reducing the number of animals used, and methods have been improved to reduce the use of lethality as an end point. However, there is as yet no validated in vitro test for acute toxicity.

We have developed a non-regulatory screen for oral acute toxicity using human cells in animal-product-free culture, and have carried out a preliminary validation using 20 cosmetic ingredients. This method is being used by companies to help build a weight-of-evidence for regulatory submissions and to avoid animal testing. We are committed to building further on this research as well as aligning with wider industry initiatives to develop animal-free approaches in this area.

In the case of the skin- and eye- specific tests, there are approved in vitro alternatives that avoid the use of animals in many cases, but these in vitro alternatives may still use animal components, like the BCOP test.

One approach that we take is to explore certain areas where we believe that we can develop new, animal-product-free tests. With the support of UK and international funding bodies, and industry partners, we are able to ensure continued progress.

Transparent communication is vital

We feel that transparency and communication are the key to building trust between Contract Research Organisations and the personal care and the wider chemical industries. If current technology does not enable a test to be conducted in a wholly animal-free way, then clearly stating this reality is essential so that companies are fully aware of the extent to which their in vitro testing programme is animal-free.

It is critical that all of us in consumer-facing industries communicate the current reality of in vitro testing to consumers in the high street and in online stores. Vegan or cruelty-free marketing positions must be founded on truth and clarity. Manufacturers of finished products should be able to provide an explanation, and evidence, of how their products and ingredients have been tested. Beyond explaining the current limitations of in vitro testing technology, it is also essential that we, both at XCellR8 and collectively as an industry, work hard to develop a pathway that leads to more scientifically relevant product testing that can truly be described as animal-free.

This article is taken from a longer piece that was due to appear in HPC Today, vol 15 (3), pp 56-59 in March 2020. Sadly, Coronavirus has put paid to that and so the article is published here with kind permission from our friends at HPC.