Styrene, environment and health

I have been asked many times. How safe is polystyrene?

There are many aspects to talk about this and lets just talk about the relationship of Styrene, the environment and health itself.

In a television programme televised by Channel NewsAsia in February this year, an A*Star scientist says that styrofoam cups use less materials across its life stages, from extraction of raw materials to its manufacture and use, compare to paper cups which uses five times more raw materials. But the survey of 1000 respondents in this programme responded with perceptions such as paper cup having least negative impact on the environment and that paper cups are recyclable.

Facts therefore say otherwise.

“In a Styrene Information & Research Centre (SIRC)-sponsored study, Dr. Martin Alexander of Cornell University demonstrated that styrene rapidly breaks down (within twelve hours) to carbon dioxide and water under aerobic conditions in soil or water.” (Alexander 1997). SIRC suggest that the natural photo-oxidation of styrene in the atmosphere results in its complete decomposition to carbon dioxide and water within approximately 24 hours.

Little data suggest that styrene would not breakdown under anaerobic conditions and even so, studies such as “EVALUATING THE RISK TO WORKERS AND THE PUBLIC FROM STYRENE EXPOSURE” by Harvard Centre for Risk Analysis panel of independent experts came to the following conclusion:

    1. “The panel concluded that epidemiology studies to date do not provide clear evidence that styrene causes cancer. But they also noted that their statistical power is inadequate to rule out an elevation in cancer consistent with the magnitude of the risk implied by the mouse lung tumor data. That is, if the mouse lung tumor findings correctly characterize the amount by which styrene exposure increases the risk of cancer in humans, the effect may be too small to have shown up in even the best and largest epidemiology studies conducted to date.” Carcinogenicity is therefore only concluded to be “suggestive”.
    2. “at levels relevant to human exposure, the evidence of non-cancer effects is more limited.”
    3. only at “Styrene exposures greater than 100 ppm have been shown to cause a variety of nervous system effects (e.g., nervous system depression, drowsiness, headaches, and disturbance of balance).”

Styrene in its solid form is known not to be biodegradable but with a low level of relevant exposure concluded by some studies on use of polystyrene product as well the availability of polystyrene recycling options are suggesting that using polystyrene as a substitute for materials such as paper can be the way forward in terms of environment sustainability.

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