Chronic toxicity study – OECD 452

Chronic toxicity studies assess the biological effects of repeated exposure to a chemical substance over a prolonged period. Unlike acute toxicity, they examine sublethal effects that can impact health in the medium or long term: reproductive impairment, metabolic effects, organ damage, abnormal behavior, etc. This test is a key regulatory requirement under REACH, the CLP Regulation, and substance safety assessment procedures.

Objective of the analysis

The purpose of this test is to:

• Determine the systemic toxic effects during prolonged exposure (often 90 days or more)
• Identify the thresholds for no observed adverse effects (NOAEL) and for no observed adverse effects (LOAEL)
• Provide data for long-term risk assessment
• Meeting regulatory requirements for the registration or evaluation of chemical substances

OECD Methodology 452

Chronic toxicity studies according to OECD guideline 452 are generally conducted in vivo on rodents (rats or mice) exposed daily to the test substance via oral, dermal, or inhalation routes. The minimum recommended duration is 90 days, but longer protocols may be implemented depending on specific requirements.

The parameters evaluated include:

• Food and water consumption
• Body weight and behavior
• Hematological and biochemical parameters
• Histopathological examination of target organs
• Reproductive, developmental or immunotoxicity data (if required)

Sectors and applications concerned

• Cosmetics : long-term safety of an active ingredient or preservative
• Chemistry : REACH registration, CMR substance notifications
• Pharmaceuticals / biotechnology : preclinical evaluation
• Agrochemicals : Regulatory studies for active substances

Why use YesWeLab?

YesWeLab connects you with specialist regulatory laboratories, accredited to conduct chronic toxicology studies in accordance with OECD 452. Our partners have animal platforms under Good Laboratory Practices (GLP), integrated histopathology capabilities, and behavioral and metabolic monitoring devices.

Our team supports you from the definition of the experimental protocol to the interpretation of the results for your REACH, CLP, or specific customer or regulatory authority requirements.

See also:

• Acute toxicity study – OECD 420/423
• Micronucleus test – OECD 487
• Mutagenicity test (Ames) – OECD 471