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ToggleAcute Toxicity Studies - Study Design of OECD Guideline 405: Acute Eye Irritation/Corrosion Study in Rabbits
The OECD Guideline 405 outlines a standardized test for assessing the potential of a substance to irritate or corrode the eyes of rabbits. This information is crucial for ensuring the safety of chemicals before they reach the market. Here’s a breakdown of the key aspects:
Objectives:
- Determine the degree of irritation/corrosion caused by a single ocular application of the test substance.
- Classify the substance according to its irritation/corrosion potential based on the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).
- Provide initial information for further safety testing, if necessary.
Test System:
- Healthy young adult albino rabbits (at least 3 per dose group) are used.
Dose Levels and Application:
- The test substance is applied to the conjunctival sac of one eye of each animal.
- The other eye remains untreated as a control.
- The amount of test substance applied depends on its expected severity:
- Liquids:1 mL
- Solids: 10 mg
- Occlusion of the eyelids may be used for certain types of substances.
Observation Period:
- Animals are observed for at least 72 hours after application.
- Detailed observations are made at specific intervals, including:
- Immediate: Redness, chemosis, corneal opacity.
- 1, 24, 48, and 72 hours: Discharge, iritis, conjunctival swelling, corneal opacity.
Scoring System:
- A scoring system is used to quantify the severity of observed effects, including redness, chemosis, corneal opacity, and other relevant factors.
- The scores for each animal and each observation time point are summed to provide an overall irritation score.
Data Analysis:
- The mean irritation score for each dose group is calculated.
- The substance is classified according to GHS criteria for irritation/corrosion categories (e.g., Category 1: irreversible damage, Category 2: reversible damage).
Benefits:
- Standardized protocol for international harmonization.
- Provides a quick and reliable assessment of eye irritation/corrosion potential.
- Relatively simple and cost-effective compared to other in vivo tests.
Limitations:
- Requires animal use, raising ethical concerns.
- Does not assess all potential eye effects (e.g., sensitization).
- May not be suitable for all types of substances (e.g., volatile or highly reactive chemicals).
Additional Resources:
- OECD Test Guideline 405:
https://www.oecd-ilibrary.org/environment/test-no-405-acute-eye-irritation-corrosion_9789264185333-en
- Acute Dermal Toxicity Testing – Guidance Document Number 24, National Toxicology Program:
https://ntp.niehs.nih.gov/sites/default/files/iccvam/suppdocs/feddocs/oecd/oecd-gd24.pdf:
- Globally Harmonized System of Classification and Labelling of Chemicals (GHS):
https://unece.org/DAM/trans/danger/publi/ghs/ghs_rev06/English/ST-SG-AC10-30-Rev6e.pdf