In this dissertation, the effect of the widely used pepper gas (oleoresin capsicum, OC) derived from the cayenne pepper was studied in the blood gases, electrolytes and some biochemical parameters on the rats with different dosages and periods. In the pre-dosage phase, 12 of 47 Wistar albino rats were used as the live material. Commercially available 90 g OC sprays were provided. It was experimentally measured that 6 g of OC was sprayed per second. 6 rats were used,as control group. Experimental Group 1 was 9 rats which were kept 5 min in an OC sprayed closed enviroment for 4 sec (24 g); Experimental Group 2 was 10 rats which were kept 8 min in an OC sprayed closed enviroment for 8 sec (48 g); Experimental Group 3 was 10 rats which were kept 15 min in an OC sprayed closed enviroment for 12 sec (72 g). The rats were kept as a group of 5 of each in 50x50x50 cm experiment cube and OC was applied for the abovementioned periods and dosages. The blood samples were taken from the heart after the 1-2 min sedation application. The potential hydrogen (pH), carbon dioxide partial pressure (pCO(2)), concentration of total carbon dioxide (ct CO2), O-2% saturation, HCO3, base excess (BE), base excess of extracellular fluid (B(ecf)), Na, K, Ca, Cl and glucose levels were measured by Rapidlab 865 System and auto analyser. When the control group values were compared to the other three groups, pH, ct CO2 and HCO3 (except the Group 3) were decreased, pCO(2), pO(2), O-2% saturation, K, Cl, glucose, BE and B(ecf) were increased and no significant change was observed in Na and Ca levels. The pH change (P <= 0.05), pO(2) (P <= 0.01), HCO3 (P <= 0.01); %O-2 saturation (P <= 0.001), K (P <= 0.05), Cl (P <= 0.05); B(ecf) (P <= 0.05) levels were evaulated the changes according to inter-group and control group. As a result, no fatality were encountered in rats which were exposed different dosages and amounts of OC in a closed enviroment except difficulty in breathing and conjuctivity. Despite that supporting biochemical changes for respiratoric asidose were encountered, it was understood that pepper gas could especially be used as a safe riot control agent in open air.