Meanwhile, compared with animal testing procedures, some in vitro methods have advantages in terms of reduced testing times and the use of artificially grown cells that have a closer similarity to human skin tissue than animal cells.

Tightening leash on testing on animals

Get beautiful without harming animals

"Indeed, many of the in vitro test methods are more specific than the traditional tests on animals and are widely considered to be more reliable," MacArthur Clark said, adding that the authorities' concerns about consumer safety may dictate the pace at which measures to phase out animal testing are introduced.

"Consumer safety is paramount, and it's important to respect the concerns of Chinese consumers and provide reassurance. This may dictate the pace at which changes will be implemented," she said.

Alice Cai, director of Life Sciences at the Research and Development Center of the French cosmetics giant L'Oreal Group, said all the company's products are developed through alternative methods. "In fact, the data we collected through animal testing couldn't accurately project the effects on human beings, especially in terms of cosmetics," she said.

"Human skin is very different from that of animals such as guinea pigs, which are covered in fur that must be removed before any tests can take place," she said.

However, because some alternative testing procedures also require the use of animal tissue, an outright ban on the use of animals is still not a practical option.

For example, the Bovine Corneal Opacity and Permeability Assay, an alternative procedure to gauge eye irritation caused by cosmetics, requires the use of bovine corneas. Although the corneas are obtained from slaughterhouses, the method is still considered an improvement on in vivo testing, which can require the use of dozens of rabbits.

"Some test methods enable scientists to use a single animal's organs to yield a large number of research results, while others require the use of hundreds of live animals. That's the difference," Zhang said.

An inevitable shift

Animal rights groups have complained that tests on live animals are not only cruel and inhumane, but can also produce inaccurate results.

The Hygienic Standards for Cosmetics, China's official rules on safety tests for cosmetics, are based on guidelines drawn up by the Organization for Economic Cooperation and Development, which stipulate that all cosmetics products must be subjected to 17 animal-based toxicological tests, including those for acute oral toxicity, acute eye irritation, skin sensitization and a combined test for chronic toxicity and carcinogenicity.

The OECD guidelines, which include a range of alternative procedures, have opened the doors for the use of in vitro methods in recent years.

"Animals are animals and human beings are human beings. The results of tests conducted on animals do not necessarily reflect the effects of the products on human beings," said Zhang from the Institute for In Vitro Sciences in the United States.

Zhang used the example of eye irritation tests, traditionally conducted on rabbits, to explain his case. "The eye conjunctiva (the transparent tissue that covers the eye) of rabbits has only four to five layers, while human beings have 12 layers. How can you expect tests on rabbits to predict the results on human beings?" he said.

Some cosmetics companies said they have long been troubled by the use of live animals in tests. "We send the same batch of products to three test agencies under different government departments and the results are always drastically different, so we don't know which result to trust," said Chen Liang, nutrition and care science manager with Biostime Inc, a Guangdong-based cosmetics company.

Chen said the company has always taken great interest in in vitro procedures because they often provide new insights into products, and some alternative methods, including in vitro, have advantages over traditional tests, such as the shorter time needed to yield results.