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|An Evaluation of the Hazards of Toys and other Products made from Polyvinyl Chloride (PVC)|
Important Update: Comparing the safety of all materials used for food and water
July, 2002: Recent questions from our email inbox
Easy-to-print version of this report (26 sec @ 28k)
Update, Jan. '99:
Understanding Phthalates - basic facts
The PVC polymer chains form an attraction to one another which produces a very rigid plastic. When a soft or flexible plastic is required, a plasticizer is added to allow the chains to slide against each other. Phthalates esters are the most commonly used in PVC. DEHP (Di-Ethylhexyl Phthalate) has been the most commonly used, and is still used as a plasticizer for all PVC medical and surgical products, such as a IV tubes, blood bags, ventilation tubes, and much else. Due to concerns about the evidence of toxicity of DEHP in laboratory animals, DEHP in children's products was replaced during the past ten years by DINP (Di-Isononyl Phthalate). Semi-rigid PVC contains about 10 percent phthalates; flexible PVC, as much as 50 percent by weight.
It is generally agreed by all researchers that phthalates are given off freely by PVC. This is caused by mechanical stress (bending, pressure, chewing), solvents such as fats, oils, saliva, and some drugs, and temperatures over 85° F, which causes it to migrate in gas form.
Phthalates migrate easily out of the PVC polymer, since it is not at all bound to the PVC molecule. DEHP is nearly insoluble in water, but highly soluble in fats and oils. When used in medical tubing, it has been found to accumulate in blood, lung, and liver tissue, as well as in fat. In fatty foods, such as butter, cheese, and prepared meat products packaged in PVC, significant amounts of DEHP or DINP have been found in surface layers. DEHP does not vaporize easily at room temperature, but does migrate out of the plastic as a vapor over 30° C (86° F), and has been found in the airstream of medical respiratory tubing. Under relatively slight pressure, phthalates will exude from PVC. As little as 1/10 kilogram per square centimeter (1.4 lb/sq. inch) can result in loss of 30% of the plasticizer. (PVC Handbook, from C. P. Hall, plasticizer manufacturer).
The CPSC and the Dutch government, in laboratory simulations of children's sucking and chewing behavior, have recently concluded that although children using PVC teethers would indeed swallow significant amounts of Phthalates, these amounts are too small on a daily basis to present a hazard.
Again, the issue is the cumulative nature of the toxic effects. Studies
of liver damage in rats have been criticized as inapplicable to humans, since
the kinds of pre-cancerous cellular changes (peroxisomes) seen in
rats with experimental short-term high dosage does not cause the same changes
in humans or other primates. But in fact, the changes do occur in
primates, including humans; it just takes longer. Dialysis patients
using PVC tubing showed peroxisomes after a year of treatment.
Clear signs of liver damage were seen in monkeys receiving transfusions over
the period of a year.
In a discussion of Phthalate toxicity,
it is worth quoting verbatim one of our sources [Ganning A.E., Brunk U.,
Dallner J. (1984) Phthalate Esters and their Effect on the Liver. Hepatology V4 No 3, Pp 541-547]
"Chronic intake and accumulation to a deleterious level may require 30 to 40 years. We have reason top believe that accumulating toxicity is valid for humans. Therefore, threshold valuesrecommended by authorities as nontoxic have little or no relevance. Extensive use of PVC materials in homes, medical care, and as food packaging material started only during the 1960's, which means that evaluation of chronic human toxicity cannot be performed until around 2000 to 2020!..."
This last paragraph suggests that by now (1999), we ought to be seeing an epidemic of liver disease and other illnesses related to the significant chronic exposure of modern industrial populations to Phthalates. There is no question that we are eating a lot of the stuff; there does remain the question of whether, in fact, it has actually done any harm to adults.
The evidence is stronger that phthalates are a danger to young infants. In a 1988 German study, preterm infants receiving respiratory assistance utilizing PVC tubing accumulated significant amounts of DEHP in their lungs, developing unusual lung disorders resembling hyaline membrane disease. The authors make the point that the livers of very young infants do not metabolize DEHP as efficiently as those of adults, placing infants at higher risk. They further suggest that the damage to testicular and related structures seen in rats may be more relevant to preterm infants than to adult humans, again because of slower/less complete metabolism.
DETERMINATION OF THE COMPOSITION AND
QUANTITIES OF PHTHALATE ESTER ADDITIVES IN PVC CHILDREN'S TOYS
Phthalates do not bind to the PVC, remaining present as a freely mobile and leachable phase in the plastic. As a consequence, phthalates are continuously lost from soft PVC over time. Contact and pressure, such as that applied during teething or play, can increase the rates at which these chemicals leach from the plastic. [The "PVC Handbook" from C. P. Hall, manufacturer of Phthalates and other plasticizers, includes data showing that plasticizers are exuded from the polymer under a minimum of pressure: .1 kg/cm2 can cause a loss of up to 30% of the plasticizer]
Children in contact with soft PVC toys may, therefore, ingest substantial quantities of phthalates during normal play, especially from toys specifically designed to be chewed. This is of concern as phthalates are known to present a number of hazards. Although acute toxicity appears to be low, phthalates have been shown to cause a range of adverse effects in laboratory animals following longer exposure, including damage to the liver and kidney and, in some cases, effects on the reproductive tract.
The limited research available to date on the composition of phthalates in PVC toys has raised concerns over the potential for exposure of children to these chemicals. Despite this, manufacturers do not provide information on the types or quantities of additives present in toys. Greenpeace was interested, therefore, to obtain a range of typical soft PVC toys from a number of countries, particularly those designed to be chewed, and to determine the types and quantities of plasticisers present.
A total of 71 toys were purchased, drawn from 17 countries, the majority of which (63) were PVC or had PVC sections. In almost all soft PVC toys analysed, phthalates comprised a sizeable proportion (most frequently 10-40%) of the total weight of the toy. Although historically the most commonly used phthalate was DEHP (di(2-ethylhexyl)phthalate), the most frequently identified, and generally most abundant, phthalate in the current investigation was the isomeric form DINP (diisononyl phthalate). Of the 63 PVC toys analysed, 40 contained DINP as the predominant phthalate, compared to only 8 for DEHP. DEHP was also present as a minor component of many of the toys containing DINP, perhaps as a contaminant in the DINP. Of the 8 non-PVC toys analysed, only one contained any detectable phthalate, and then only in trace quantities (possibly as a contaminant from the PVC in which it was packaged).
Although less well researched than DEHP, DINP shows similar toxicological properties in laboratory animals. Effects recorded include liver and kidney disorders, damage to the reproductive tract, increased incidence of certain forms of cancer and diverse effects on development and metabolism. More recently, research has revealed that DINP, along with some other phthalates, shows weak activity as a mimic of the hormone estrogen in human cell lines. When purchased for laboratory use, DINP is labelled with a number of hazard phrases, including "harmful by inhalation, in contact with skin and if swallowed", "possible risk of irreversible effects" and "may cause cancer". In contrast, toys containing up to 40% by weight DINP in a readily leachable form are frequently labelled "non toxic".
A number of other compounds were identified in some of the toys, generally at lower but significant concentrations. DBP (dibutyl phthalate) and BBP (butylbenzyl phthalate), found in several toys, are known to be particularly hazardous. The estrogenic chemical nonylphenol was isolated from 13 toys, while 2 toys were found to contain the fungicide Fungitrol 11 (Folpet).
The rates at which chemicals leach from soft PVC were not determined in this study. Nevertheless, the presence of these chemicals in such quantities in toys designed to be chewed by babies and young children, along with published evidence that such additives are hazardous and can leach from PVC toys, raises serious concerns. The Danish EPA has recently demonstrated that the leaching of phthalates, particularly DINP, from teething toys can be substantial. This has been supported by similar studies in other countries and has led, in some cases, to recommendations that certain toys be withdrawn or even that the use of soft PVC in toys for young children should be discontinued.
The study carried out by Greenpeace has demonstrated that phthalates, particularly DINP and DEHP, are widely and abundantly used in high contact children's toys. Their use represents a significant potential for exposure of children to chemical hazards, of particular concern during sensitive periods of development. Although it is practically impossible to make accurate predictions of dose, exposure to such hazards is clearly unacceptable. The only way to avoid direct intake of phthalates is to eliminate the use of PVC in all soft toy applications.