OECD Test 101 – Determination of the UV-Visible Spectrum of a Substance

The OECD 101 test determines the UV-Visible absorption spectrum of a chemical substance between 290 and 800 nm, in accordance with OECD guidelines . This spectrum is obtained by measuring the absorbance of a homogeneous solution or suspension of the substance in a suitable solvent using a UV-Vis spectrophotometer.

The objective is to identify the maximum absorption wavelengths (λmax) in order to assess the sensitivity of the molecule to light and its phototransformation potential . This data is crucial in the context of environmental assessment, photodegradation , phototoxicity , or to guide other tests (e.g. OECD 102, 113 or 316).

The measurements are carried out under standardized conditions (quartz cuvette, background spectrum, concentration adapted to linear absorbance) according to good laboratory practices (GLP) . In case of insolubility or instability, an adaptation of the method is proposed according to OECD recommendations.

OECD Test 101: Frequently Asked Questions

– What substances can be analyzed with the OECD 101 test?

The OECD 101 test is mainly applicable to organic or inorganic substances soluble in UV-transparent solvents (water, ethanol, acetonitrile, etc.). In cases of low solubility or turbidity, adaptations of the method can be proposed. It is particularly used for active ingredients (plant protection, biocides, pharmaceuticals), cosmetic ingredients, synthetic intermediates or industrial additives.

– Is this test mandatory for a REACH or biocide dossier?

The OECD 101 test is often required in REACH registration dossiers or under the Biocides Regulation (BPR) . It allows the potential photo-instability of a substance to be assessed and determines the need for additional tests (e.g., phototransformation, phototoxicity). The absence of UV-Vis data can be considered a regulatory gap .

– What is the difference between the OECD 101 test and a simple UV spectrum?

The OECD 101 test follows a standardized methodology validated by the OECD, with strict criteria on concentration, solvent selection, spectral resolution and quality of results. Unlike a simple routine UV spectrum, this test provides reproducible, regulatory interpretable and GLP-compliant , usable in registration dossiers.

At YesWeLab, we collaborate with a rigorously selected network of laboratories, most of which are certified and/or accredited (ISO 17025, COFRAC, etc.). These laboratories are chosen based on your specific needs, the matrices to be analyzed, and the required analytical techniques or methods.
If you have any specific requirements, please do not hesitate to specify them when submitting your request: our scientific team will do everything possible to respond accurately and responsively.
Since 2020, many manufacturers, distributors, and design offices have trusted us to manage their analyses, entrusting us with their samples via our digital platform.
To find out more or submit a specific request, contact our team now.