the quality of not thinking or worrying enough about the possible results of what you do

It was an act of gross irresponsibility to leave someone who wasn't properly trained in charge of the machine. 让没有经过适当培训的人负责机器是严重的不负责任的行为。

This is a shameful example of corporate irresponsibility. 这是一个可耻的毫无责任感的公司的例子。