Vice Commerce Minister Zhong Shan warned yesterday that any increase in the renminbi exchange rate risks driving Chinese exporters out of business, the Wall Street Journal reported. He said that while most exporters were able to absorb the appreciation of the renminbi that occurred in 2005, others were forced to close. He said that the profit margin on many Chinese exports is lower than 2%, and that even an incremental change upwards would produce "fundamental changes" to the condition of China’s exporters. "Water doesn’t boil if it is heated to 99 degrees Celsius," he said. "But it will boil if it is heated by one more degree." Zhong’s comments were derided as "classic protectionism" by an aide attached to the US senate’s Democratic leadership.