BCOP LLBO for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage

Scope of the method

The Method relates to
  • Human health
The Method is situated in
  • Regulatory use - Routine production
Type of method
  • In vitro - Ex vivo
This method makes use of
  • Animal derived cells / tissues / organs
Species from which cells/tissues/organs are derived


Method keywords
  • eye irritation
  • opacitometer
  • OECD TG 437-update 2020
  • Category 1
  • No Category
  • opacity
Scientific area keywords
  • regulatory toxicology
  • regulatory use
  • eye irritation
Method description

In order to find a solution for the center-weighted opacity reading associated with the OP-KIT opacitometer, a prototype of a laser light-based opacitometer (PLLBO) allowing better measurement of opacities was developed (Van Goethem et al., 2010; Annex 1). The technical optimization and optical characteristics of this device can be found in the paper by Verstraelen et al. (Verstraelen et al., 2013; Annex 2). The LLBO uses a monochromatic laser light source and has the advantage of analysing the complete corneal surface, and is therefore able to detect more efficiently opaque spots located around the periphery of the excised corneas. The different devices result in a different read-out and different threshold values that distinguish between the different irritation categories (Verstraelen et al., 2013, 2018).

Lab equipment


Method status
  • Currently submitted for further validation by an external party (e.g. OECD, EURL ECVAM,…)

Pros, cons & Future potential

  • Laser (monochromatic) light ;
  • One light source (one beam) ;
  • The whole cornea is analysed ;
  • Linear ;
  • The width of the light beam can be adjusted.

Non planned.

References, associated documents and other information


Van Goethem, F., Hansen, E., Sysmans, M., De Smedt, A., Vanparys, P., Van Gompel, J. (2010). Development of a new opacitometer for the bovine corneal opacity and permeability (BCOP) assay. Toxicol. In Vitro 24:1854-1861

Verstraelen, S., Jacobs, A., De Wever, B., Vanparys, P. (2013). Improvement of the Bovine Corneal Opacity and Permeability (BCOP) assay as an in vitro alternative to the Draize rabbit eye irritation test. Toxicol. In Vitro 27: 1298–1311

Verstraelen, S., Maglennon, G., Hollanders, K., Boonen, F., Adriaens, E., Alépée, N., Drzewiecka, A., Gruszka, K., Kandarova, H., Willoughby, J.A., Guest, R., Schofield, J., Van Rompay, A.R., 2018a. Reprint of “CON4EI: Bovine Corneal Opacity and Permeability (BCOP) test for hazard identification and labelling of eye irritating chemicals.” Toxicol. Vitr. 49, 53–64. https://doi.org/10.1016/j.tiv.2018.03.005

Adriaens, E., Van Rompay, A.R., et al., Verstraelen, S. (2019). Overall performance and multi-laboratory validation of Bovine Corneal Opacity and Permeability (BCOP) Laser Light-Based Opacitometer (LLBO) test method with regard to solid and liquid chemicals testing, Manuscript under preparation

Associated documents
BCOP TG 437_0.pdf
OECD TG No. 437

Contact person

An Van Rompay


Vlaamse Instelling voor Technologisch Onderzoek (VITO)
Flemish Region