Acute toxic class method

Acute toxic class method for acute oral toxicity testing EU... 

Acute Oral Toxicity - Acute Toxic Class Method (Updated Guideline, adopted 20 December 2001)... 

Acute oral toxicity - Acute toxic class method 2001... 

The guidance document offers a comparison of TG 420 (Fixed Dose Method), TG 423 (Acute Toxic Class Method), and TG 425 (Up-and-Down Procedure). The purpose of this Guidance Document is to provide information to assist with the choice of the most appropriate Guideline to enable particular data requirements to be met while reducing the number of animals used and animal suffering. The Guidance Document also contains additional information on the conduct and interpretation of test guidelines 420, 423, and 425. 

As mentioned above, a NOAEL is usually not derived in acute toxicity smdies. It is more usual that the only numerical value derived is the LD50 or LC50 value. The LD50 or LC50 values (or the discriminating dose if the Fixed Dose Procedure was used or the result of the Acute Toxic Class Method) give an indication of the relative lethal potency of a substance. The slope of the dose-response curve is a particularly useful parameter as it indicates the extent to which reduction of exposure will reduce the lethality the steeper the slope, the greater the reduction in response for a particular finite reduction in exposure. 

Schlede E, Genschow E, Spielmann H, Stropp G, Kayser D (2005) Oral acute toxic class method a successful alternative to the oral LD50 test. Regul Toxicol Pharmacol 42(1) 15-23. doi 10.1016/j.yrtph.2004.12.006... 

Culling, T. (2005) Ethyl ti-[[5-methyl-2-(isopropyl)cyclohexyl]carbonyl]glyclnate Acute oral toxicity In the rat—acute toxic class method. Unpublished report prepared by SafePharm Laboratories, Derbyshire, United Kingdom, for the Flavor and Extract Manufacturers Association, Washington, DC, USA. Submitted to WHO by the International Organization of the Flavor Industry, Bmssels, Belgium (SPL Project No. 1044/066). 

Acute mammalian Acute toxic class method In vivo... 

OECD, 2001b, Test Guideline 423, Acute Oral Toxicity—Acute Toxic Class Method. 

A Guidance Document on Acute Inhalation Toxicity Testing is being developed and presently exists as a draft (OECD 2004b). The document recommends the Acute Toxic Class (ATC) Method with a group size of three animals per sex, if the objective of the test is solely related to hazard classification. Limits for particle-size distribution of aerosolized test substances are suggested. The preferred mode of exposure is the nose-only, head-only, or head/nose-only exposure technique, because this mode of exposure minimizes exposure or uptake by noninhalation routes. 

Destruction of chemical warfare agents is another application for Na/NHa detoxifrcatioa Cost effective methods, other than combustion, are needed to dispose of aging stockpiles of chemical weapons. In extensive testing, the chemical agents GA, GB, GD, GF, Lewisite, VX, HD, HT, HN-1, HN-2, HL, picric acid, CG and CK have been destroyed with efficiencies greater that 99.9999% by Commodore. The reaction products have been characterized. The product mixtures were found to be CLASS 1 or CLASS 0 level materials when tested for acute toxicity. Scheme 4 illustrates the destruction of VX by rapid electron transfer to VX followed by 70% P-S and 30% C-S cleavage with evolution of ethane. 

The two standards specify slightly different tests and follow different methodologies. The USP Class VI test method consists of acute systemic (over the tissue), intracutaneous (under the skin), and muscle implantation (in the muscle) tests. Establishing a USP Class VI rating has little bearing on whether the product will win approval from the Food and Drug Administration (FDA). The Class VI rating merely states that the products exhibit a low level of toxicity under the test conditions. 

We completed acute bioassays with Daphnia pulex for 35 representative and related chemicals from the following top-ranked classes for which available toxicity data were deemed inadequate to evaluate the hazard of the classes (National Fisheries Center - Great Lakes 1986 Perry 1985) polyaromatic hydrocarbons (PAHs), alkyl halides, mono- and polycyclic alkanes, heterocyclic nitrogen compounds, other nitrogen-containing compounds, and silicon-containing compounds (alkylether silanes). The acute bioassays with Daphnia pulex followed the methods of National Fisheries Center - Great Lakes (1986) with the temperature at 20° C. 

---