Animals in Science / Research

What is the Draize Test?

Background

In 1944, the Draize test was invented as a way to measure skin and eye irritancy of chemicals and other products. Specifically, this test involves dropping concentrated amounts of a test substance into an animal’s eye (while their lids are clipped open) or placing a chemical onto an area where the animal’s skin has been shaved. The resulting irritation, which may include ulceration, inflamed/bleeding skin, swollen eyes, and blindness, is subsequently measured on a numerical scale. 

This test has been heavily criticized for shortfalls in predictability, reproducibility, and subjectivity. Although it is performed on a relatively small number of animals, the Draize test is considerably one of the cruelest test methods that individual animals are forced to endure. Victims of this test may be immobilized for up to 14 days, sometimes without any pain medication.

Numerous in vitro tests for skin and eye irritation have been developed, validated, and internationally recognized by agencies including ICCVAM, ECCVAM, and OECD.  The tests include methods that are likely to be more predictive of human responses (i.e. synthetic skin) and are undeniably more efficient and humane.

Draize Predictability Argument

The Draize test is a poor predictor of human response because of structural differences between human and rabbit eyes and due to the subjective analysis of data. To illustrate this point, here are some facts: 

  • A rabbit’s eye is anatomically and physiologically different than a human’s eye.  For example, rabbits produce fewer tears than humans do, so their eyes cannot easily flush out test chemicals.  A rabbit’s cornea is substantially thinner and more easily damaged than a human cornea and covers a greater surface area (25%) than that of a human eye (7%).[1] 
  • A 2004 study by the U.S. Scientific Advisory Committee on Alternative Toxicological Methods analyzed the modern Draize skin test, and found that tests were 10.3%-38.7% likely to misidentify a serious irritant as a mild irritant. [2]
  • The Draize method of assessing eye and skin damage is based on the investigator’s subjective interpretation of damage, and results may vary significantly between individual investigators and laboratories. Therefore, the data may be unreliable.

Impact

Since 2005, the FDA has stated that the Draize test data was no longer needed for primary skin and eye irritancy.[3] Despite no longer required by the FDA, the Draize test is still evidentially being used. From 2011-2014 the FDA approved 137 new compounds, 24% of which were tested for skin irritancy and 22% for eye irritancy.[4] The Draize test was used in 94% of all skin irritation and 60% of all eye irritation testing.[5] 

Following a protest campaign in the 1980s, consumer awareness drove many companies to abandon the test altogether.[6]  The rise of cruelty-free cosmetics/personal care companies has also contributed to reduction of Draize usage. However, there are still hundreds of other chemicals that fall outside the scope of cosmetics/personal care, including: dishwashing liquid, cleaning agents, pesticides, and other product ingredients.

Although the total number of animals used in the Draize test is relatively small, the level of suffering per animal is substantial. It has been described as “the most cruel and infamous experiments on rabbits known to mankind.”[7]  Test subjects are immobilized and therefore restrained from pawing at their eyes or skin to relieve discomfort. Furthermore, anesthesia is not required.

Feasibility

  • Availability of Alternatives: There are numerous in vitro and ex vivo replacements which could potentially eliminate perceptions of necessity for the Draize test. These alternatives have been scientifically validated and accepted to replace animal tests for eye and skin irritation. Examples include:  
    • In vitro: In 2013, the development of a new in vitro eye testing method called the Human Corneal Epithelium model was announced [8] which uses actual human cornea cells and is therefore expected to produce more predictive results. 
    • Ex vivo: alternatives include ICE (Isolated Chicken Eye) test and BCOP (Bovine Corneal Opacity and Permeability) test.
  • Current Use: Although the FDA stated that the Draize test was no longer “required,” companies have continued to utilize it at their discretion. Considering the availability of alternative test methods, possible reasons for their continued usage include: lack of information and/or accessibility, industrial pressures, and subjective resistance to change.
  • Reduction/Replacement Trend: The availability of the Draize test has been substantially reduced in other countries through legislation that prohibits animal testing for cosmetics. For example, India passed a law that specifically mandates replacement of the Draize test with alternative test methods. 

Citations: 
[1] Stephen R. Kaufman, M.D. Problems with the Draize Test, http://www.safermedicines.org/reports/Perspectives/vol_1_1989/Problems%20with%20the%20Draize.html. Accessed January 15, 2018.
[2] William S. Stokes, Preliminary Evaluation of the Underprediction Rate of the In Vivo Dermal Irritation Test Method, U.S. Scientific Advisory Committee on Alternative Toxicological Methods (2004).
[3] BioPharmaDIVE Press Releases, Coalition for FDA: Draize Rabbit Test for Skin and Eye Irritation Not Required (May 26, 2016) https://www.biopharmadive.com/press-release/20160526-coalition-for-fda-draize-rabbit-test-for-skin-and-eye-irritation-not-requi/. Accessed January 12, 2018.
[4] Summary Minutes from the September 16, 2014 SACATM Meeting, Research Triangle Park, NC at page 20 citing to Dr. Jacobs, FDA PowerPoint, Alternative Methods in CDER/FDA (Nov 2005); as cited by E. Baker et al, The Food and Drug Law Institute (FDLI) Food and Drug Policy Forum: How Regulatory Updates Allowing for More Modern Test Methods, Pragmatic Validation of Preclinical Test Methods, and FDA Guidances Will Lead to the Advancement of More Predictive Preclinical Testing Tools, Efficiency, and Safer and More Effective Drugs (2015).
[5] K. Archibald, T. Drake, R. Coleman, Barriers to the Uptake of Human-based Test Methods and How to Overcome them, ATLA 43, 301-308 (2015).
[6] Scientific American, Do Companies Still Test on Live Animals?  https://www.scientificamerican.com/article/cosmetics-animal-testing/. Accessed January 10, 2018.
[7] The Hindu BusinessLine, Health Ministry outlaws obsolete test on rabbits, quoting Alokparna Sengupta, Deputy Director of HSI/India (November 7, 2016) http://www.thehindubusinessline.com/economy/policy/health-ministry-outlaws-obsolete-test-on-rabbits/article9315912.ece. Accessed January 10, 2018.
[8] HSI, Be Cruelty-Free Campaign Welcomes New In vitro Method That Could Replace Painful Rabbit Eye Tests In Cosmetics Industry (August 20, 2013) http://www.hsi.org/news/news/2013/08/bcf_welcomes_alternative_082013.html?referrer=http://www.hsi.org/issues/becrueltyfree/facts/blinded_rabbits.html?referrer=https://www.google.com/. Accessed January 12, 2018.