4 ONLINE TOPICS Vol.15 No.5 STN <1.> O STN O 2 REGISTRY 1 STN 4 () MSDS-OHS MSDS-CCOHS RTECS HSDB MSDS 2 MSDS RTECS ALL () RTECS HSDB LD50 NH 2 RTECS HSDB Cl Cl O NIOSH NLM O Cl Cl Registry of Toxic Effects Hazardous Substances of Chemical Substances Data Bank RTECS IARC 153,125 4 4,560 4 1 83 100 RN * * CAS CAS CAS REGISTRY RTECS ONLINE TOPICS Vol.15 No.5 5 HSDB CAS * TOX (86 ) WLN Cl Cl O O Cl Cl CAS NIOSH (TEL : 03-5978-3621) RTECS STN 6 WLN STN 2001 4 2001 7 CAS 16:00 8:00 FIZ 19:00 7:00 22:00 8:00 6 1 STN CAS FIZ STN STN