Aviado D M, Smith D G
Toxicology. 1975;3(2):241-52. doi: 10.1016/0300-483x(75)90088-8.
The low-pressure propellants influence predominantly the circulation, whereas the high pressure propellants affect the respiration in anesthetized monkeys. There are four groups according to the level of toxicity: Class 1, low-pressure propellants of high toxicity that cause tachycardia and hypotension; Class 2, low-pressure propellants of intermediate toxicity that influence either circulation or respiration or both; Class 3, high-pressure propellants of intermediate toxicity that cause bronchoconstriction; and Class 4, high-pressure propellants of low toxicity that do not influence respiration or circulation even when inhaled at levels of up to 20 percent concentration.
低压推进剂主要影响循环系统，而高压推进剂则影响麻醉猴子的呼吸系统。根据毒性水平可分为四类：第1类，高毒性低压推进剂，可导致心动过速和低血压；第2类，中等毒性低压推进剂，影响循环系统或呼吸系统或两者皆有影响；第3类，中等毒性高压推进剂，可导致支气管收缩；第4类，低毒性高压推进剂，即使以高达20%的浓度吸入也不影响呼吸或循环系统。
