Shanghai, 11 February (Argus) — South Korean petrochemical producer YNCC's No.3 naphtha cracker at its Yeosu complex suffered an explosion today that killed four workers. The 9.26am (12:26 GMT) incident resulted in another four workers hospitalized with serious or minor injuries, according to fire department authorities. YNCC had been carrying out tests on a heat exchanger at the cracker following maintenance. The No.3 cracker produces 500,000 t/yr of ethylene and 270,000 t/yr of propylene at full production capacity. YNCC also operates two other crackers at Yeosu, the 900,000 t/yr No.1 and 880,000 t/yr No.2. Their operations have unaffected by.