Acute Precutaneous toxicity study on rats

1. Test purpose:

Master the pesticide’s toxicity effects that direct contact to the test animals brings partial skin damnification and poisoning from head to foot. Determine the LD50 according to the test results to provide reference to safeguard during pesticide manufacture and application.

2. Materials and method:

2.1 test pesticide: Cymoxanil was provided by Saturn Agrochemical Inc.

2.2 test animals: 40 SD health rats with body weight 250~300g. All rats were provided by Nanjing Medical University Animals Center. All the animals were fed in clean and sterilized stainless steel cage. Both diet and water standard met the requirements for experiment animals. Environment temperature of feeding animals was 20±2℃, humidity was 50%-80 % and it was well ventilated.

2.3 test method: According to Horn method, SD rats were divided randomly into 4 groups with each 5 rats per sex at room temperature. Each rat was removed hair with 4×4 square centimeter on the back 24h prior to test. Cymoxanil was diluted to different designed dosage with salad oil. Rats from every group were daubed Cymoxanil on the back without air at the doses of 215, 464,1000, and 2150mg/kg, respectively according to 0.2ml/100gb.w.. Cover with gauze and plastic film, then fix with transparent adhesive tape after treatment. Remove adhesive tape and film and wash off with soap water 4h later. Observe and record poisoning symptom and mortality circumstance for two weeks. Weigh every 3d during whole observation period.

3. The results:
After dosing, No death appeared in highest dosage group (2150mg/kg). Main poisoning symptoms included reducing action and cachexia. Bodyweight of survival recovered or increased 3d later. Dissection results showed no macroscopic pathological changes in every essential organ.
The test showed that LD50 (4h) for rat is more than 2000mg/kg. Cymoxanil was classified as low toxic pesticide.
Results are as follows:

Note: the results is only fit for the sample

Test: check: principal