You can't apply for 'Qualifying Test' without passing of "The Environmental protection and safety course".
If you have not yet  taken "The Environmental protection and safety course", please check following information. 
1) Registration Period  : 5th Auguest 2013~15th Auguest 2013
access the site below.
http://ieps.snu.ac.kr/
but all of that is in Korean.But your labmates will know how to register the course.
you may want to ask some help to your labmates.
2) Course date  : Feb. 18th ~ Feb. 19th (for 2days)
Class D (for foreign students) - Multimedia auditorium Bldg. 83, Rm. 404

check the attachment file.