But in 2006, the situation reversed, in concert with a wider commodities boom.
Regarding wider commodities, Mr Rogers says their prices will also likely rise further this year, as investors continue to buy them at a time when governments risk weakening currencies through their work to boost economic growth.
Polypropylene is one of the widest spread commodity polymers in plastic industry with an estimated global consumption of 62.4 million tons in 2020.
Futures are now used to trade a wide variety commodities, including oil, gas, precious metals, Treasury bonds and foreign currencies.
Speculators were also attracted to the precious metals markets as part of a wider bet on commodity prices.
February also brought a record-breaking 2.4% jump in monthly average prices by non-fuel retailers, as firms passed on the VAT hike and wider increases in commodity prices to consumers.
If investors prefer to bet directly on a wide range of commodity prices, Mr. Herbst recommends the Harbor Commodity Real Return Strategy fund, which started trading in September.
Metabolic engineering offers the opportunity to produce a wide range of commodity chemicals that are currently derived from petroleum or other non-renewable resources.
Robert Brown, who directs the Bioeconomy Institute at Iowa State University, Ames, says the new work is noteworthy because chemical companies have many decades of experience in using heat and catalysts to convert petroleum into a wide variety of commodity chemicals.
