McDonald's voluntarily stopped the use of CFCs (which destroy the ozone layer) as blowing agents (chemicals used to blow tiny holes in the plastic, making it moldable) in the beaded version of the foam in 1988. They replaced CFCs with Benzene and ethylene Both flammable and toxic, these two killers are the petroleum and natural gas products that go to make styrene, the base material for polystyrene foam. The EPA identified ethylene and benzene, the chemical precursors to polystyrene as the 4th and 6th highest waste production processes respectively. Benzene is a known carcinogen, and both are highly flammable.
Recent studies of Styrene distribution in human tissue have startling results. Long term exposure (3.2 to 10 years) to small quantities of styrene (1 to 10 parts/million, whereas a person manufacturing polystyrene may receive 50 to 100 ppm over an 8 hr. period) cause a wide spectrum of adverse health effects including neurotoxic, hematological (low platelet and hemoglobin values), cytogenetic (chromosomal and cytogenic abnormalities) and carcinogenic effects. Neurotoxic effects include fatigue, nervousness, difficulty sleeping, poor performance on memory and stimuli response tests and nerve conduction velocity abnormalities. Other effects include low platelet and hemoglobin values, chromosomal and lymphatic abnormalities at levels below 50 ppm.
Neurotoxic damage is as serious if not more serious than carcinogenic impact. Chemicals like styrene are known to indiscriminately attack tissue and the nervous systems. With growing evidence that ailments like Parkinson's Disease are linked to man-made toxins, the public should take all necessary steps to reduce exposure to neurotoxins. Parkinson's Disease may not often kill people, but this degenerative brain disorder will rob a person of intelligence and hamper speech, walking, and the ability to perform simple tasks. Therefore, it would appear wise to avoid using polystyrene products when consuming food and beverages.
A 45-year old man exposed to styrene monomer vapors for a period of five years developed a burning sensation in the lower portion of his feet and a feeling of walking on inflated balloons of cotton. Upon examination, there was evidence of total demyelination, (destruction, removal or loss of the myelin sheath of nerves). Therefore, serious physical destruction to the nervous system occurred, leaving the nerves exposed without protection. The authors of the study concluded that "styrene affects the nervous system to a greater degree than formerly thought."
Another study of neurotoxicity of toluene and styrene notes that these "aromatic hydrocarbons have unsuspected long lasting neuological effects. The accumulation of these highly lipid-soluble materials in the lipid-rich tissues of the brain, spinal cord, and peripheral nerves was apparently correlated with acute or chronic functional impairment of the nervous system.
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Last modified: 4 Mar 1996