OECD Test Guidelines

401 Acute Oral Toxicity (Deleted Guideline, date of deletion 20 December 2002) 

402 Acute Dermal Toxicity (Updated Guideline, adopted 24 February 1987) 

403 Acute Inhalation Toxicity (Original Guideline, adopted 12 May 1981) 

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Identification of gaps in existing OECD Test Guidelines for these endpoints. 

D]ata generated in the testing of chemicals in an OECD Member country in accordance with OECD Test Guidelines and OECD Principles of Good Laboratory Practice shall be accepted in other Member countries for purposes of assessment and other uses relating to the protection of man and the environment. 

OECD. Test guideline 428 Skin Absorption In Vitro Method, OECD, Paris, 2004. 

OECD, Skin absorption in vitro method. OECD Test Guideline 428, Paris, 2004. Wagner, H., et ah. Drug distribution in human skin using two different in vitro test systems comparison with in vivo data. Pharm. Res., 17, 1475-81, 2000. 

Klein, W., Kordel, W., Weip, M., and Poremski, H.J. Updating of the OECD test guideline 107 partition coefficient-octanol/water OECD laboratory intercomparison test of the HPLC method, Chemosphere, 17(2) 361-386, 1988. Klemenc, A. and Low, M. Die Loslichkeit in Wasser und ihr Zusammenhang der drei Dichlorbenzole. Line Methode zur Bestimmung der Loslichkeit sehr wenig loslicher und zugleich sehr fluchtiger Stoffe, Rec. Trav. Chim. Pays-Bas, 49(4) 629-640, 1930. 

Cunha GCP (2005) Evaluation of mechanisms inducing thyroid toxicity and the ability of the enhanced OECD Test Guideline 407 to detect these changes. Arch Toxicol 79 390 05... 

The harmonized test guidelines have been developed for use in the testing of pesticides and toxic substances, and the development of test data that must be submitted to the US-EPA for review under Federal regulations. The OPPT guidelines are based on the OECD test guidelines (Section 2.2.6) however, minor deviations may occur. The guidelines are available for download at the OPPT Web site (US-EPA 2006d). 

The testing methods working area of the EU is closely linked and coordinated with the parallel OECD Test Guidelines program. 

According to the definitions provided in the OECD test guidelines (TG 420 and 423), acute oral toxicity refers to those adverse effects that occur following oral administration of a single dose of a substance or multiple doses given within 24 h. 

There are six OECD test guidelines concerning acute toxicity, one of which (TG 401) has now been deleted because of concerns for animal welfare and the number of animals used. Although this test guideline is now deleted, the toxicologist needs to be familiar with the method, as chemicals have been tested according to TG 401 up to the point of deletion. 

The EU test guidelines for acute toxicity testing, the Annex V methods, are similar to the corresponding OECD test guidelines. 

In the OECD test guideline for acute dermal irritation/corrosion (OECD TG 404), the following definitions are provided ... 

In the EU test guidelines for acute dermal irritation/corrosion (Annex V B.4) and for acute eye irritation/corrosion (Annex V B.5), the dehnitions for dermal and eye irritation/corrosion are identical to those provided in the respective OECD test guidelines (Section 4.5.1.1). 

In the OECD test guideline for skin sensitization (OECD TG 406), the following definition is given Skin sensitization (allergic contact dermatitis) is an immunologically mediated cutaneous reaction to a substance. In the human, the responses may be characterized by pruritis, erythema, edema, papules, vesicles, bullae, or a combination of these. In other species, the reactions may differ and only erythema and edema may be seen. ... 

There are currently three OECD test guideline methods for test of skin sensitization in animals. These include the Guinea-Pig Maximization Test (GPMT), the Buehler test, and the murine Local Lymph Node Assay (LLNA). 

Table 4.12 summarizes the various OECD test guideline studies for repeated dose toxicity in more detail, including the parameters examined in each test, in order to provide a brief overview of the similarities and differences between the various repeated dose toxicity studies. 

Overview of In Vivo Repeated Dose Toxicity OECD Test Guideline Studies... 

The 1998 OECD test guidelines for the oral 28-/90-day studies (see Table 4.12) examine a number of simple nervous system endpoints, e.g., clinical observations of motor and autonomous nervous system activity, and histopathology of nerve tissue. It should be recognized that the standard 28-/90-day tests measure only some aspects of nervous system stmcture and function, while other aspects, e.g., learning and memory and sensory function is not or only superficially tested. Primarily the standard 28-/90-day tests are intended as a screening for neurotoxicity and depending on the results, further testing may be needed. 

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