Johor Fire and Rescue Department has identified 15 types of chemicals in air samples taken from areas surrounding Sungai Kim Kim, including hydrogen cyanide.<br /><br />Its director Datuk Yahaya Madis said while most of these gases were harmless, some – such as hydrogen cyanide – could be harmful if found in high concentration or if a person was exposed to it for too long.<br /><br />He said currently, based on their tests, the concentration of hydrogen cyanide was at a safe level of 3ppm.
