Many of our customers prefer to use the classical Ocular Irritection® protocol to evaluate the irritant potential of their surfactants for GHS and CLP classification.
We at INT.E.G.RA., as European Training Center and partners of InVitro International, recommend the use of the OECD protocol, Test Guideline OECD 496, because of its greater accuracy.
New studies by IVRO (Table 2.) reveal that when the two methods were used to evaluate the properties of typical surfactants, the new OECD methodology provided results more consistent with published standards.
This new protocol is based on the traditional Irritection® protocol with some variations, mainly in the incubation time of the preparation, which increases from five hours to twenty-four. (Table 1.).
Table 1. Technical Differences Between the Original 5H Surfactant Sample Preparation and the Current Methodology OECD 496
| Parameter |
Classic Protocol |
OECD 496 |
| (1) Dilution | Dilute the substance to 1%, 5%, 10%, 25% and 50%. | Dilute the substance to a 5% working solution first and then perform a two-fold serial dilution to obtain the following final concentrations: 5%, 2.5%, 1.25%, 0.625% and 0.3125%. |
| (2) Activator amount | 60 µl/mL (3X) | 20 µl/mL (1X) |
| (3) Disc Application | Insert the disc into the wells with blank and protein reagent solution before applying the sample. | Insert the disc into the well after the sample had been applied. Incubate with the disc in place. |
| (4) Dose/Concentration | Apply 125 µl of each dilution of the test substrate into the disc. | Apply 125 µl of each dilution of the test substrate directly into the corresponding blank and protein reagent solutions. |
| (5) Incubation time | 5 hours | 24 hours |
From the comparative studies carried out, it is evident that these variants of the Ocular Irritection method for surfactant substances are also improved in the case of mixtures and compounds with surfactant characteristics.
Table 2. Comparison Results Obtained with the Original Surfactant Sample Preparation and the Current Methodology OECD 496
Click on the table to enlarge
