Acute Oral Toxicity Study of GAL-57 (Bentazon + Dicamba) Herbicide in Rats

Abstract

An acute oral toxicity study of the herbicide GAL-57 (Avalon), a mixture of bentazon and dicamba as active ingredients, was investigated on rats, using a new method that has been used in the past several years (2001). Clinical observations symptoms and mortality were performed for all animals in different time intervals after treatment, and gross necropsy was performed at the end of observation period. Clinical symptoms (decreased activity, prone position, abnormal limb position, decreased righting reflex, decreased grip and limb tone, decreased body and abdominal tone, dyspnoea) of marked degree were noted after administration of 2000 mg/kg, and animals were dead in the period of 30-60 minutes after the treatment. GAL-57 did not cause any clinical sings at single 300 mg/kg bw dose. The physical condition and behaviour of animals (males and females) were normal, and it is not differ in reaction to the control. According to the methodology used in the present study, it could be concluded that the acute oral LD-50 value of the GAL-57 proved to be between 300 and 2000 mg/kg body weight in rats, and the product was ranked into Poison group III according to Serbian criteria, category 4 of the Global Harmonized Classification System, and Category III of the EPA classification.

Akutna oralna toksičnost herbicida (preparata) GAL-57 (Avalon), koji je mešavina dve aktivne materije, bentazon i dikamba, ispitivana je na pacovima primenom nove metode koja se koristi tek nekoliko godina (od 2001. godine). Praćeni su simptomi trovanja i smrtnost životinja u različitim intervalima nakon doziranja, a po završetku perioda opservacije obavljene su odgovarajuće patohistološke analize. Kod životinja koje su dobijale preparat GAL-57 u dozi od 2000 mg/kg, registrovana je pojava veoma izraženih simptoma trovanja kao što su: smanjena aktivnost, nekoordinirano kretanje, opušten položaj zadnjih nogu (koje vuku pri kretanju), smanjen refleks, smanjen tonus udova i čitavog tela, dispneja. Simptomi se postepeno intenziviraju, a životinje uginjavaju u periodu 30-60 minuta posle tretiranja. Kod životinja koje su dobijale preparat GAL-57 u dozi od 300 mg/kg nije bilo uginjavanja, niti su registrovane pojave kliničkih simptoma trovanja. Njihova fizička aktivnost i ponašanje (i kod mužjaka i kod ženki) nisu se značajnije razlikovali u odnosu na kontrolne životinje. Po metodologiji korišćenoj u ovim ispitivanjima može se zaključiti da se LD-50 herbicida GAL-57 kreće između 300 i 2000 mg/kg, pa prema tome preparat može biti razvrstan po našim kriterijumima u III grupu otrova, u kategoriju 4 po kriterijumima Globalno usaglašenog sistema klasifikacije (Globally Harmonized Classification System), odnosno u kategoriju III po klasifikaciji EPA (Environmental Protection Agency).