.icon {

background-image: url('sprite-alert-black.png');

}

.icon-ic_error_black_24dp {

background-position: -5px -5px;
width: 24px;
height: 24px;

}

.icon-ic_warning_black_24dp {

background-position: -39px -5px;
width: 24px;
height: 24px;

}