OECD guidelines refer to standardized experimental protocols, developed by the Organisation for Economic Co-operation and Development, to govern the safety testing of chemical substances. They rigorously define the methods to be followed to assess essential properties such as toxicity, biodegradability, bioaccumulation, and effects on human health and the environment.
Every year, thousands of new compounds are introduced to the market, requiring reliable, comparable data accepted by international regulatory authorities. Guidelines enable laboratories to perform tests according to OECD standards and produce this data within a harmonized scientific and regulatory framework. In this article, we offer a comprehensive overview of their organization, applications, and central role in laboratory analyses.
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Table of Contents
What is the OECD and what is its role in chemical safety?
An organization at the heart of global regulatory cooperation
Founded in 1961, the OECD now comprises 38 member countries and several international partners. While its role is often associated with economic issues, the OECD is also a leading authority in the field of chemical safety. For over 40 years, it has been developing harmonized standards for assessing the risks of chemical substances to humans and the environment. These standards are compiled in the “OECD Guidelines for Chemical Testing,” a set of scientific methods intended for industrial, academic, and government laboratories.
These guidelines cover a wide range of properties: toxicity, ecotoxicity, biodegradability, bioaccumulation potential, physicochemical characteristics… They serve as the basis for most international regulations: REACH regulation in Europe, TSCA in the United States, regulations for biocidal products, cosmetics or plant protection products.
The MAD system: data pooling and test reduction
One of the major advances introduced by the OECD in the field of chemical testing is the MAD (Mutual Acceptance of Data) system. This system allows a test carried out according to OECD guidelines and the principles of Good Laboratory Practice (GLP) in one member country to be recognized as valid by all other countries adhering to the system, without the need for replication.
To date, 38 member countries and 7 non-member countries (including Argentina, Brazil, China, India, and South Africa) participate in the MAD system. This mechanism allows for estimated annual savings of over €309 million by avoiding analytical duplication and accelerating the marketing of tested substances.
A commitment to science, quality and ethics
OECD guidelines do not simply standardize methods; they also guarantee data quality . All tests performed according to these guidelines must comply with GLP (Good Laboratory Practice) principles , a set of rules governing the conduct of studies: traceability of results, validation of equipment, staff training, data archiving, etc.
Another fundamental point: by promoting alternative methods (in vitro tests, in chemico tests, defined approaches), the OECD actively participates in the reduction of animal experimentation , in accordance with the principles of the 3Rs (Replace, Reduce, Refine).
The guidelines are therefore much more than a regulatory tool: they embody a scientific and ethical commitment to a better assessment of chemical substances worldwide.
Understanding the structure of OECD guidelines: four technical sections
The OECD guidelines for testing chemicals are not a uniform set but are rigorously organized into four main sections , identifiable by the number assigned to each test. This classification allows for the structuring of analytical methods according to the nature of the parameters studied, whether they be physicochemical characteristics, biological effects, or environmental behavior. Each section corresponds to a specific theme, essential for establishing a complete toxicological and ecotoxicological profile of a substance.
Section 1: Physico-chemical properties (numbered from 100 onwards)
The first section groups together tests focusing on the fundamental characteristics of chemical substances. These parameters directly influence the behavior of a molecule in biological or environmental settings. Examples include:
- The melting point (OECD 102), the boiling point (OECD 103) or the density (OECD 109), essential for handling and formulating substances.
- Water solubility ( OECD 105) and vapor pressure (OECD 104) are used to estimate environmental exposure.
- The octanol/water partition coefficient (OECD 107, 117, 123), a key indicator of bioaccumulation potential.
- Viscosity , surface tension , dissociation constant , and the dissolution behavior of polymers .
The data from this section are used upstream of toxicological studies. In particular, they allow for modeling the (water, air, soil) or biological (skin, mucous membranes) compartments
In recent years, particular emphasis has been placed on the analysis of nanomaterials , with specific tests such as OECD 124 (specific surface area), OECD 125 (particle size), and OECD 126 (hydrophobicity index). These tests aim to better understand the emerging risks associated with these particular chemical forms.
Section 2: Effects on biological systems (numbered from 200)
The second section comprises ecotoxicological tests , which assess the impact of a chemical substance on living organisms , primarily non-human. They are essential for characterizing environmental hazards , particularly in the sectors of plant protection products, biocides, and industrial substances.
Among the benchmark tests:
- Acute or chronic toxicity on daphnia (OECD 202, 211), fish (OECD 203, 210, 229), or algae (OECD 201).
- Tests on earthworms (OECD 207, 222), terrestrial plants (OECD 208, 227), or bees (OECD 213, 245) for substances for agricultural use.
- Bioassays on bacteria , protozoa , springtails , or even benthic aquatic organisms such as chironomids (OECD 218, 233).
This section also contains a wealth of methods for screening for endocrine disruptors , a major concern in public health and regulatory assessment. Examples include:
- The XETA test (OECD 248) on amphibian development,
- The uterotrophic bioassay in rats (OECD 440),
- Reproductive tests on transgenic zebrafish (OECD 250).
The diversity of model species used makes it possible to assess effects at different trophic levels and to best reflect potential risks to ecosystems.
Section 3: Development and behavior in the environment (numbered from 300)
This third section focuses on fate analysis , that is, the environmental fate of substances. It aims to understand how a compound interacts with environmental matrices, how it transforms, migrates, or accumulates.
Among the most common tests:
- Easy biodegradability tests (OECD 301) and intrinsic (OECD 302 A/B/C), which assess the ability of microorganisms to decompose the substance.
- Bioaccumulation studies (OECD 305, 315, 317), which measure the concentration of a substance in the tissues of an exposed organism.
- Phototransformation tests (OECD 316), anaerobic transformation in sediments (OECD 308) or in slurry (OECD 320).
- More targeted methods such as the OECD 313 test, dedicated to emissions from treated wood , or tests on nanomaterials in a simulated environment (OECD 318).
This data is essential to feed exposure prediction models and to assess the persistence of a substance (criterion “P” in the PBT framework: persistent, bioaccumulative, toxic).
Section 4: Effects on human health (numbering from 400)
The fourth section is probably the largest and most strategic for the chemical, pharmaceutical, and cosmetic industries. It includes tests designed to assess potential effects on human health through different exposure scenarios (oral, dermal, inhalation).
It includes:
- Acute toxicity ( OECD 401 to 403), repeated dose studies (OECD 407 to 413),
- Reproductive toxicity and developmental toxicity tests (OECD 414 to 443),
- Genotoxicity tests such as the micronucleus test (OECD 474), bacterial mutations (OECD 471), or chromosomal aberrations (OECD 473 to 475),
- And alternative methods: in vitro , in chemico , reconstructed human epidermis , or mechanistic assays ( OECD 428 , 431, 439, 456, 493…).
These tests are essential for compiling REACH regulatory dossiers , obtaining marketing authorizations , or ensuring consumer safety .
In summary, this four-section structure covers all dimensions of chemical hazard and risk. We will explore each section in detail.
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Physico-chemical properties: analyze the fundamental characteristics of substances (OECD 100+ tests)
Objectives and importance of physicochemical tests
The OECD 100 series tests allow for the precise characterization of chemical substances in terms of their basic physical and chemical properties. This data is essential for assessing the behavior, stability, hazard, and regulatory classification of substances. It is used, in particular, for REACH registration dossiers, safety data sheets (SDS), and notifications under the CLP Regulation.
Parameters analyzed in OECD 100+ trials
Physicochemical tests cover a range of key parameters such as:
- The melting point and the boiling point
- Water solubility
- Vapor pressure
- The n-octanol/water partition coefficient (log Kow)
- Density
- Viscosity
- Specific surface area
- The size and distribution of particles
This information allows us to assess mobility in the environment, bioaccumulation, or even the formulation of finished products.
Focus: Nanomaterial-specific tests
Some tests in the 100 series are designed for nanomaterials, with parameters such as particle size, hydrophobicity, and specific surface area by volume. This data is crucial for anticipating the potential reactivity of these substances at the nanoscale, particularly in the cosmetics, agrochemical, and innovative materials sectors.
Laboratory analytical methods
Laboratories use various techniques to perform these analyses, including:
- chromatography (HPLC) is used to measure the partition coefficient or molar mass.
- Permeable gel chromatography , to determine the molecular weight distribution of polymers
- methods (UV-VIS) to analyze absorption
- Conventional gravimetric and volumetric tests for parameters such as density or solubility
These analyses are carried out according to standardized protocols to guarantee the traceability and comparability of results between accredited laboratories.
OECD 100+ Test Summary Table
These tests provide the essential scientific foundations for assessing the hazard of a chemical substance and anticipating its industrial or environmental uses.
| OECD Reference | Description FR | Description EN |
|---|---|---|
| OECD 101 | UV-VIS absorption spectra | UV-VIS Absorption Spectrum |
| OECD 102 | Melting point/melting range | Melting Point/Melting Range |
| OECD 103 / OECD 103 | Boiling point | Boiling Point |
| OECD 104 | Vapor pressure | Vapor Pressure |
| OECD 105 / OECD 105 | Water solubility | Water solubility |
| OECD 106 / OECD 106 | Adsorption/desorption (successive equilibria method) | Adsorption – Desorption Using a Batch Equilibrium Method |
| OECD 107 / OECD 107 | n-octanol/water partition coefficient: bottle shaking method | Partition Coefficient (n-octanol/water): Shake Flask Method |
| OECD 108 / OECD 108 | Ability to form complexes in water | Complex Training Ability in Water |
| OECD 109 / OECD 109 | Density of liquids and solids | Density of Liquids and Solids |
| OECD 110 / OECD 110 | Particle/fiber size distribution | Particle Size Distribution / Fiber Length and Diameter Distributions |
| OECD 111 / OECD 111 | Hydrolysis depending on pH | Hydrolysis as a Function of pH |
| OECD 112 / OECD 112 | Dissociation constant in water | Dissociation Constants in Water |
| OECD 113 / OECD 113 | Selection test for thermal and air stability | Screening Test for Thermal Stability and Stability in Air |
| OECD 114 / OECD 114 | Viscosity of liquids | Viscosity of Liquids |
| OECD 115 / OECD 115 | Surface tension of aqueous solutions | Surface Tension of Aqueous Solutions |
| OECD 116 / OECD 116 | Liposolubility of solid and liquid substances | Fat Solubility of Solid and Liquid Substances |
| OECD 117 / OECD 117 | n-octanol/water partition coefficient: HPLC method | Partition Coefficient (n-octanol/water), HPLC Method |
| OECD 118 / OECD 118 | Average molecular weight and distribution of polymers by GPC | Number-Average Molecular Weight and Molecular Weight Distribution by GPC |
| OECD 119 / OECD 119 | Low molecular weight polymer content | Low Molecular Weight Content of a Polymer Using Gel Permeation Chromatography |
| OECD 120 / OECD 120 | Polymer dissolution/extraction behavior in water | Solution/Extraction Behavior of Polymers in Water |
| OECD 121 / OECD 121 | Estimation of the adsorption coefficient (Koc) by HPLC | Estimation of the Adsorption Coefficient (Koc) using HPLC |
| OECD 122 / OECD 122 | Determination of pH, acidity and alkalinity | Determination of pH, Acidity and Alkalinity |
| OECD 123 / OECD 123 | n-octanol/water partition coefficient: slow stirring method | Partition Coefficient (n-octanol/water): Slow-Stirring Method |
| OECD 124 / OECD 124 | Specific surface area by volume of nanomaterials | Volume Specific Surface Area of Manufactured Nanomaterials |
| OECD 125 / OECD 125 | Particle size and particle size distribution of nanomaterials | Nanomaterial Particle Size and Size Distribution |
| OECD 126 / OECD 126 | Hydrophobicity of nanomaterials | Determination of the Hydrophobicity Index of Nanomaterials |
Effects on biological systems: assessing the impact on living organisms (OECD 200+ tests)
Objectives and scope of ecotoxicological tests
The OECD 200 series tests aim to assess the toxicity of chemical substances on various living organisms representative of aquatic and terrestrial ecosystems. They are essential for estimating the environmental risks associated with the use or release of chemicals, particularly within the framework of regulatory assessments for biocides, plant protection products, or substances subject to REACH.
These tests make it possible to characterize acute or chronic effects on aquatic animals, pollinating insects, plants, soil microorganisms and invertebrates.
Examples of iconic tests
The most commonly used tests include:
- OECD 201 : Inhibition of the growth of algae and cyanobacteria
- OECD 202 : Immediate immobilization of Daphnia magna (freshwater crustacean)
- OECD 203 : Acute toxicity in fish
- OECD 207 : Acute toxicity in earthworms
- OECD 213 & 214 : Acute toxicity in the honeybee (oral and contact routes)
- OECD 221 & 227 : Inhibition of terrestrial plant growth (Lemna, vigor tests)
These tests make it possible to characterize the sensitivity of bioindicator species, which play a key role in the food chain and the functioning of ecosystems.
Methods and types of effects evaluated
The OECD 200+ trials cover different types of biological effects:
- Acute toxicity : mortality or immobilization in the short term (48-96h)
- Chronic effects : reproduction, growth, development
- Endocrine disruption : estrogenic/androgenic activity, amphibian metamorphosis
- Alteration of biological functions : transformation of nitrogen or carbon by soil microorganisms
The methods are standardized and rely on controlled exposure conditions (fresh water, sediments, soil…) to guarantee the reliability of the results.
Integration into regulatory strategies
The results of these tests are used in environmental risk assessments of chemical substances. They are required in registration dossiers for:
- REACH and CLP Regulations
- Biocides Directive (EU) 528/2012
- Regulation (EU) 1107/2009 on plant protection products
Data from ecotoxicological tests also make it possible to establish limit concentrations, safety factors or environmental hazard classifications.
OECD 200+ Test Summary Table
These tests are an essential foundation for establishing a robust ecotoxicological profile of substances, and for meeting the growing demands for transparency and environmental safety.
| OECD Reference | Description FR | Description EN |
|---|---|---|
| OECD 201 / OECD 201 | Freshwater algae and cyanobacteria, growth inhibition assay | Freshwater Alga and Cyanobacteria, Growth Inhibition Test |
| OECD 202 / OECD 202 | Daphnia sp., immediate immobilization trial | Daphnia sp. Acute Immobilization Test |
| OECD 203 / OECD 203 | Fish, acute toxicity test | Fish, Acute Toxicity Test |
| OECD 204 / OECD 204 | Fish, prolonged toxicity (14 days) | Fish, Prolonged Toxicity Test: 14-Day Study |
| OECD 205 / OECD 205 | Birds, diet-related toxicity test | Avian Dietary Toxicity Test |
| OECD 206 / OECD 206 | Birds, breeding attempt | Avian Reproduction Test |
| OECD 207 / OECD 207 | Earthworm, acute toxicity tests | Earthworm, Acute Toxicity Tests |
| OECD 208 / OECD 208 | Terrestrial plant trial: seedling emergence and growth | Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test |
| OECD 209 / OECD 209 | Activated sludge, respiration inhibition trial | Activated Sludge, Respiration Inhibition Test |
| OECD 210 / OECD 210 | Fish, toxicity test in the early life stages | Fish, Early-life Stage Toxicity Test |
| OECD 211 / OECD 211 | Daphnia magna, reproduction attempt | Daphnia magna Breeding Test |
| OECD 212 / OECD 212 | Fish, embryonic toxicity and fry | Fish, Short-term Toxicity Test on Embryo and Sac-Fry Stages |
| OECD 213 / OECD 213 | Honeybee, acute oral toxicity | Honeybees, Acute Oral Toxicity Test |
| OECD 214 / OECD 214 | Honeybee, acute toxicity by contact | Honeybees, Acute Contact Toxicity Test |
| OECD 215 / OECD 215 | Fish, juvenile growth | Fish, Juvenile Growth Test |
| OECD 216 / OECD 216 | Soil microorganisms: nitrogen transformation | Soil Microorganisms: Nitrogen Transformation Test |
| OECD 217 / OECD 217 | Soil microorganisms: carbon transformation | Soil Microorganisms: Carbon Transformation Test |
| OECD 218 / OECD 218 | Chironomids in a water-sediment system (contaminated sediment) | Sediment-Water Chironomid Toxicity Using Spiked Sediment |
| OECD 219 / OECD 219 | Chironomids in a water-sediment system (contaminated water) | Sediment-Water Chironomid Toxicity Using Spiked Water |
| OECD 220 / OECD 220 | Reproduction attempt in the enchytrae | Enchytraeid Reproduction Test |
| OECD 221 / OECD 221 | Lemna sp., growth inhibition assay | Lemna sp. Growth Inhibition Test |
| OECD 222 / OECD 222 | Reproduction in earthworms | Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei) |
| OECD 223 / OECD 223 | Acute oral toxicity in birds | Avian Acute Oral Toxicity Test |
| OECD 224 / OECD 224 | Inhibition of anaerobic bacteria (digested sludge) | Inhibition of Anaerobic Bacteria in Digesting Sludge |
| OECD 225 / OECD 225 | Toxicity to Lumbriculus in a water-sediment system | Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment |
| OECD 226 / OECD 226 | Reproduction of a predatory mite in the soil | Predatory mite (Hypoaspis aculeifer) Reproduction Test in Soil |
| OECD 227 / OECD 227 | Terrestrial plants: vegetative vigor | Terrestrial Plant Test: Vegetative Vigor Test |
| OECD 228 / OECD 228 | Developmental toxicity in dung flies | Developmental Toxicity to Dipteran Dung Flies |
| OECD 229 / OECD 229 | Short-term reproduction in fish | Fish Short Term Reproduction Assay |
| OECD 230 / OECD 230 | 21-day trial in fish: estrogen and androgen screening | 21-day Fish Assay: Estrogenic/Androgenic Activity Screening |
| OECD 231 / OECD 231 | Metamorphosis of amphibians | Amphibian Metamorphosis Assay |
| OECD 232 / OECD 232 | Reproduction in springtails | Collembolan Reproduction Test in Soil |
| OECD 233 / OECD 233 | Toxicity to the life cycle of midges | Chironomid Life-Cycle Toxicity Test |
| OECD 234/ OECD 234 | Sexual development of fish | Fish Sexual Development Test |
| OECD 235 / OECD 235 | Immediate immobilization: Chironomus sp. | Chironomus sp., Acute Immobilization Test |
| OECD 236 / OECD 236 | Acute embryonic toxicity in fish (FET) | Fish Embryo Acute Toxicity (FET) Test |
| OECD 237 / OECD 237 | Larval toxicity in the honeybee | Honey Bee Larval Toxicity Test |
| OECD 238 / OECD 238 | Toxicity of Myriophyllum Spicatum (without sediment) | Sediment-Free Myriophyllum Toxicity Test |
| OECD 239 / OECD 239 | Toxicity of Myriophyllum Spicatum (water-sediment) | Water-Sediment Myriophyllum Toxicity Test |
| OECD 240 / OECD 240 | Reproduction in one generation in the medaka (MEOGRT) | Medaka Extended One Generation Reproduction Test |
| OECD 241 / OECD 241 | Growth of amphibian larvae (LAGDA) | Larval Amphibian Growth and Development Assay |
| OECD 242 / OECD 242 | Reproduction in Potamopyrgus antipodarum | Potamopyrgus antipodarum Reproduction Test |
| OECD 243 / OECD 243 | Reproduction in Lymnaea stagnalis | Lymnaea stagnalis Reproduction Test |
| OECD 244 / OECD 244 | Inhibition of protozoa in activated sludge | Protozoan Activated Sludge Inhibition Test |
| OECD 245 / OECD 245 | Honeybee: chronic oral toxicity (10 days) | Honey Bee Chronic Oral Toxicity Test |
| OECD 246 / OECD 246 | Bumblebee: acute toxicity by contact | Bumblebee, Acute Contact Toxicity Test |
| OECD 247 / OECD 247 | Bumblebee: acute toxicity via oral route | Bumblebee, Acute Oral Toxicity Test |
| OECD 248 / OECD 248 | Thyroid assay on Xenopus elepheroid embryos | Xenopus Eleutheroembryonic Thyroid Assay (XETA) |
| OECD 249 / OECD 249 | Acute toxicity in fish cell line (RTgill-W1) | Fish Cell Line Acute Toxicity – RTgill-W1 Assay |
| OECD 250 | Detection of endocrine disruptors in zebrafish (EASZY) | EASZY Assay – Transgenic Zebrafish Estrogen Response Assay |
| OECD 251 / OECD 251 | Rapid androgen screening (RADAR) | Rapid Androgen Disruption Activity Reporter Assay |
| OECD 252 / OECD 252 | Rapid in vivo estrogen screening (REACTIV) | Rapid Estrogen Activity In Vivo Assay |
| OECD 253 / OECD 253 | Juvenile hormonal activity on Daphnia magna (JHASA) | Juvenile Hormone Activity Screening Assay using Daphnia magna (JHASA) |
Becoming in the environment: understanding the persistence, migration and accumulation of substances (OECD 300+ tests)
Objectives and challenges of the environmental future study
The OECD 300 series tests are designed to determine what happens to a substance once it is released into the environment. This includes its degree of biodegradability , its potential for bioaccumulation , and its stability or decomposition in different compartments (soil, water, sediments, air). This data is essential for predicting the long-term impacts of chemicals and for building environmental dispersal models.
Environmental fate assessment is also a regulatory prerequisite in REACH dossiers or assessments of biocidal and phytopharmaceutical active substances.
Types of environmental tests
OECD 300+ trials are divided into several main categories:
- Easy and intrinsic biodegradability (e.g. OECD 301, 302): they assess the ability of microorganisms to decompose a substance under standardized conditions.
- Bioaccumulation (e.g. OECD 305, 315, 317): they measure the concentration of a product in exposed organisms, which provides information on its potential accumulation in the food chain.
- Aerobic and anaerobic transformation (e.g. OECD 307, 308, 320): these tests simulate the behavior of the substance in different environments (soil, sediments, manure).
- Leaching or photolysis tests : these allow us to estimate the mobility of substances or their degradation under the effect of light.
These tests may also include mathematical models (calculation of Koc for soil/water distribution, half-life , etc.) to extrapolate the data to ecosystem scales.
Specific characteristics related to nanomaterials
Nanomaterials present a particular analytical challenge: their behavior is influenced by their specific surface area, size, and state of aggregation. The OECD 318 evaluates their dispersion stability in simulated environmental media, a key parameter for estimating their persistence or mobility.
The study of the fate of nanomaterials in the environment requires a combined approach including experimental tests and specific models (colloids, particle-substrate interactions, etc.).
Associated analytical methods
Environmental testing relies on a wide range of analytical techniques, including:
- Gas or liquid chromatography coupled with mass spectrometry (GC-MS, LC-MS/MS) to track degradation products.
- Elemental analysis (C/N) for monitoring organic carbon or nitrogen losses.
- CO₂ or methanogenic gas production to estimate microbial activity.
- Spectroscopy or particle dynamics (DLS) in the case of nanomaterials.
These techniques guarantee accurate quantification, even at low concentrations, and allow the fate of substances to be reconstructed under controlled conditions.
OECD 300+ trial summary table
These tests are a central tool for predicting the environmental behavior of substances, particularly in environmental risk , bioaccumulation and toxicity persistence (BBT) , and environmental fate modeling . They make it possible to determine whether a substance is likely to accumulate in natural environments or, conversely, to degrade rapidly, and thus to guide risk management measures.
| OECD Reference | Description FR | Description EN |
|---|---|---|
| OECD 301 / OECD 301 | Easy biodegradability | Ready Biodegradability |
| OECD 302 A / OECD 302 A | Intrinsic biodegradability: modified SCAS method | Inherent Biodegradability: Modified SCAS Test |
| OECD 302 B / OECD 302 B | Intrinsic biodegradability: Zahn-Wellens/EMPA test | Inherent Biodegradability: Zahn-Wellens/EVPA Test |
| OECD 302 C / OECD 302 C | Intrinsic biodegradability: modified MITI test (II) | Inherent Biodegradability: Modified MITI Test (II) |
| OECD 303 / OECD 303 | Simulation test – Aerobic wastewater treatment | Simulation Test – Aerobic Sewage Treatment |
| OECD 304 A / OECD 304 A | Intrinsic biodegradability in soil | Inherent Biodegradability in Soil |
| OECD 305 | Bioaccumulation in fish | Bioaccumulation in Fish: Aqueous and Dietary Exposure |
| OECD 306 / OECD 306 | Biodegradability in seawater | Biodegradability in Seawater |
| OECD 307 / OECD 307 | Aerobic and anaerobic transformation in the soil | Aerobic and Anaerobic Transformation in Soil |
| OECD 308 / OECD 308 | Aerobic and anaerobic transformation in aquatic sediments | Aerobic and Anaerobic Transformation in Aquatic Sediment Systems |
| OECD 309 | Aerobic mineralization in surface waters | Aerobic Mineralization in Surface Water – Simulation Test |
| OECD 310 / OECD 310 | Easy biodegradability – CO₂ release (free space test) | Ready Biodegradability – Headspace CO₂ Test |
| OECD 311 / OECD 311 | Anaerobic biodegradability in digested sludge | Anaerobic Biodegradability in Digested Sludge |
| OECD 312 / OECD 312 | Leaching on soil columns | Leaching in Soil Columns |
| OECD 313 / OECD 313 | Emissions from treated wood into the environment | Emissions from Preservative-Treated Wood |
| OECD 314 / OECD 314 | Simulation of biodegradability in wastewater | Simulation Tests to Assess Biodegradability in Wastewater |
| OECD 315 / OECD 315 | Bioaccumulation in benthic oligochaetes | Bioaccumulation in Sediment-Dwelling Benthic Oligochaetes |
| OECD 316 / OECD 316 | Phototransformation of chemicals in water | Phototransformation of Chemicals in Water – Direct Photolysis |
| OECD 317 / OECD 317 | Bioaccumulation in terrestrial oligochaetes | Bioaccumulation in Terrestrial Oligochaetes |
| OECD 318 / OECD 318 | Dispersion stability of nanomaterials | Dispersion Stability of Nanomaterials in Simulated Environmental Media |
| OECD 319 A / OECD 319 A | Intrinsic clearance in vitro (trout hepatocytes) | Intrinsic Clearance Using Rainbow Trout Hepatocytes (RT-HEP) |
| OECD 319 B / OECD 319 B | Intrinsic clearance in vitro (S9 fraction of trout liver) | Intrinsic Clearance Using Rainbow Trout Liver S9 Fraction (RT-S9) |
| OECD 320 / OECD 320 | Anaerobic transformation in manure | Anaerobic Transformation of Chemicals in Liquid Manure |
| OECD 321 / OECD 321 | Bioconcentration in Hyalella azteca | Hyalella Azteca Bioconcentration Test (HYBIT) |
Effects on human health: predicting toxicity and risks to humans (OECD 400+ tests)
Objective of the tests: to guarantee safety for users and consumers
The OECD 400 series comprises regulatory tests designed to assess the effects of chemical substances on human health. These tests allow for the characterization of different types of toxicity:
- Acute toxicity : immediate effects after a single exposure (oral, dermal, inhaled).
- Subchronic and chronic toxicity : cumulative effects of repeated exposure over several weeks or months.
- Genotoxicity and mutagenicity : potential damage to DNA, mutation, chromosomal aberration.
- Reprotoxicity : disruption of fertility or embryonic development.
- Endocrine or immunotoxic effects : alteration of hormonal or immune system functions.
These tests are mandatory in the procedures for registering substances (REACH, CLP), cosmetic safety assessment (Regulation (EC) No. 1223/2009), or for the authorization to place on the market biocidal and pharmaceutical products.
Methods used: in vivo, in vitro and alternatives
The first OECD tests in this series (401 to 426) are mainly carried out in vivo on an animal model , in strict compliance with Good Laboratory Practices (GLP) .
However, methods have evolved significantly since the 2000s, with a shift towards alternative methods :
- In vitro on reconstituted human cell cultures (skin, eye, liver, etc.).
- In chemico , simulating predictable chemical reactions with biomolecules.
- Biological or computational simulation models (QSAR, read-across).
These methods aim to reduce animal testing while maintaining a high level of scientific accuracy. Several OECD guidelines (430+, 440+, 490+ series) are dedicated to integrating these approaches.
Industrial application areas
OECD 400+ tests are essential for a wide range of industries:
- Cosmetics industry : skin/eye irritation tests (OECD 431, 439, 492), sensitization (OECD 442).
- Biocidal industry : acute multi-route toxicity (OECD 402 to 420), reproduction tests (OECD 443).
- Pharmaceutical industry : reproductive toxicity, neurotoxicity (OECD 414, 426), carcinogenicity (OECD 451 to 453).
- Chemical and materials industry : safety data sheets (SDS), CLP classification.
All these tests must be carried out under GLP conditions , in accredited laboratories, and fully documented to meet regulatory requirements.
Summary table of the main OECD 400+ tests
These tests are central to the processes of assessing risks to human health , particularly in the cosmetics, biocides, cleaning product, medical device , and any other product sectors, whether the product comes into direct or indirect contact with humans. The use of OECD-validated methods ensures scientific and regulatory compliance with international requirements.
| OECD Reference | Description FR | Description EN |
|---|---|---|
| OECD 401 / OECD 401 | Acute oral toxicity | Acute Oral Toxicity |
| OECD 402 | Acute skin toxicity | Acute Dermal Toxicity |
| OECD 403 | Acute inhalation toxicity | Acute Inhalation Toxicity |
| OECD 404 / OECD 404 | Skin irritation/corrosion | Acute Dermal Irritation/Corrosion |
| OECD 405 | Eye irritation | Acute Eye Irritation/Corrosion |
| OECD 406 | Skin sensitization | Skin Sensitization |
| OECD 407 / OECD 407 | Oral toxicity at repeated doses over 28 days | Repeated Dose 28-day Oral Toxicity Study in Rodents |
| OECD 408 | Oral toxicity 90 days (rodents) | Repeated Dose 90-Day Oral Toxicity Study in Rodents |
| OECD 414 / OECD 414 | Prenatal developmental toxicity | Prenatal Developmental Toxicity Study |
| OECD 416 / OECD 416 | Reproductive toxicity across two generations | Two-Generation Reproduction Toxicity Study |
| OECD 420 / OECD 420 | Acute oral toxicity (predetermined method) | Acute Oral Toxicity – Fixed Dose Procedure |
| OECD 421 / OECD 421 | Reproductive and developmental toxicity screening | Reproduction/Developmental Toxicity Screening Test |
| OECD 422 / OECD 422 | Combined study toxicity and reproduction | Combined Repeated Dose Toxicity and Reproduction/Developmental Screening Test |
| OECD 429 / OECD 429 | Awareness: lymph node test | Local Lymph Node Assay |
| OECD 431 / OECD 431 | In vitro skin corrosion (human skin model) | In Vitro Skin Corrosion: Reconstructed Human Epidermis |
| OECD 439 / OECD 439 | in vitro skin irritation | In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method |
| OECD 440 / OECD 440 | Uterotrophic Bioassay in Rodents | Uterotrophic Bioassay in Rodents |
| OECD 442 AE / OECD 442 AE | In vitro/in chemico skin sensitization tests | Skin Sensitization Assays (LLNA, KeratinoSens, DPRA…) |
| OECD 451 / OECD 451 | Carcinogenicity studies | Carcinogenicity Studies |
| OECD 452 / OECD 452 | Chronic toxicity studies | Chronic Toxicity Studies |
| OECD 455 / OECD 455 | Estrogen receptor transactivation (in vitro) | Estrogen Receptor Transactivation Assays |
| OECD 471 / OECD 471 | Mutation assay on bacteria (Ames test) | Bacterial Reverse Mutation Test |
| OECD 473 / OECD 473 | Chromosomal aberrations in vitro | In Vitro Mammalian Chromosomal Aberration Test |
| OECD 474 / OECD 474 | Mammalian micronucleus test | Mammalian Erythrocyte Micronucleus Test |
| OECD 487 / OECD 487 | in vitro micronuclei | In Vitro Mammalian Cell Micronucleus Test |
| OECD 490 / OECD 490 | Gene mutation on the TK gene | In Vitro Mammalian Cell Gene Mutation Tests Using Thymidine Kinase |
| OECD 492 / OECD 492 | In vitro ocular irritation on reconstituted human corneal epithelium | Reconstructed Human Cornea-like Epithelium (RhCE) Test Method |
| OECD 493 / OECD 493 | Recombinant human estrogen receptor | Human Recombinant Estrogen Receptor Binding Assays |
| OECD 497 / OECD 497 | Defined approaches for skin sensitization | Defined Approaches for Skin Awareness |
Why use an expert laboratory for OECD tests?
Mastering scientific and regulatory complexity
OECD tests, whether they focus on physicochemical properties, ecotoxicology, environmental fate, or human toxicology, require a high level of scientific rigor. They involve :
- standardized experimental protocols with strict requirements,
- a nuanced interpretation of the results , within a statistical and regulatory framework,
- and specific know-how depending on the type of matrix, substance, or industrial application.
An experienced laboratory will not only be able to carry out the test in accordance with the appropriate OECD guideline, but also support the manufacturer in choosing the relevant tests , preparing the samples, and formatting the results for regulatory dossiers (REACH, CLP, biocides, cosmetics…).
Compliance with GLP/ISO 17025 requirements and traceability
For the results to be acceptable to the authorities (ECHA, ANSES, EFSA, etc.), it is imperative that the tests be carried out:
- in laboratories accredited according to ISO 17025 ,
- according to Good Laboratory Practices (GLP) ,
- with complete traceability of raw data, procedures, equipment used, etc.
These safeguards are essential for the data to be used in registration, authorization or risk assessment processes.
Case study: YesWeLab, a facilitator of regulatory testing
YesWeLab is a digital platform specializing in the management and outsourcing of laboratory analyses for industry. Thanks to its network of over 200 partner laboratories across Europe, all accredited to GLP and/or ISO 17025 standards , YesWeLab enables:
- quickly find a competent laboratory for the required OECD test (even the most specific ones like OECD 315 or 443),
- manage the technical and regulatory exchanges between the client and the laboratory,
- , sample traceability, and deadlines in real time
- to obtain usable reports for REACH, biocides, plant protection products, cosmetics, etc. dossiers.
This model greatly simplifies the processes for manufacturers, especially small and medium-sized structures that do not always have an internal regulatory department.
Saving time and ensuring compliance for manufacturers
By using YesWeLab, you will benefit from:
- access to cutting-edge analytical skills ,
- saving time in the search for qualified service providers,
- and regulatory quality assurance across the entire analytical chain.
In a context where regulatory pressure is intensifying in Europe (REACH, CLP, BPR, Cosmetics Regulation), this expertise is a real lever for compliance, cost optimization and reduction of time to market.
