Frequently Asked Questions About Phthalate Esters

American Chemistry Council
Phthalate Esters Panel

1. What are phthalate esters?
2. Are phthalate esters safe in vinyl products?
3. How do plasticizers do their job?
4. Where will the average person come into contact with flexible vinyl in their homes?
5. Would most flexible vinyl household products contain phthalate esters?
6. Does the plasticizer industry believe vinyl is necessary and beneficial?
7. Why is flexible vinyl different from other plastics?
8. Are consumers at risk from coming into contact with vinyl products containing phthalates?
9. It appears that animal testing has shown some phthalates to be carcinogens, and others to cause kidney and liver effects. Are these compounds a threat to our health?
10. Don't some phthalates cause effects on the liver, such as increased liver weights? Are these known human effects?
11. How do government agencies establish acceptable levels of exposure for chemicals?
12. What is the endocrine disruption hypothesis?
13. Why are phthalates frequently listed as potential endocrine disruptors?
14. Have the phthalates used in toys been tested for their ability to mimic estrogen?
15. Is the endocrine disruption hypothesis valid, or simply an extension of chemophobia?
16. Would the Panel endorse labeling products that contain phthalate esters?
17. The toy manufacturers made a pledge in the mid-80s to remove one particular phthalate ester, DEHP, from their products. Was this because of a demonstrated risk to children?
18. Some organizations are suggesting parents avoid toys with phthalates. Do you agree?
19. Haven't some European countries banned toys containing phthalates?
20. What's currently happening with the European Commission on this issue?
21. Is the Consumer Product Safety Commission investigating phthalates in toys?
22. Is the American Chemistry Council committing a great many resources to handle public concerns about phthalate esters?
23. Has ACCincreased its dialogue with regulatory agencies about these issues over the last year?
24. What are the plasticizer industry views on the use of these compounds?

What are phthalate esters?

Phthalate esters are liquid plasticizers, similar in appearance to vegetable oils, which are added to a hard plastic called polyvinyl chloride (PVC or vinyl). The liquid phthalates act as a softener causing the plastic to become flexible. For example, hard PVC with no plasticizer could be a pipe under a sink or the vinyl siding of a house. When plasticizers are added, a wide range of products can be created such as toys, wire and cable, flooring and shower curtains. Vinyl is actually the second most popular plastic in the world as a result of its durability, low cost and versatility.

Are phthalate esters safe in vinyl products?

Producers of phthalates are committed to manufacturing safe products. For 25 years, phthalates have been researched and tested so they can be used safely. Based on the best evidence to date, the Phthalate Esters Panel strongly believes phthalates are safe and pose no hazard for children or adults when properly used in vinyl products. The Panel is committed to continued research and testing of phthalate esters and will work closely with government agencies so that these products can continue to be used safely.

How do plasticizers do their job?

It's simple. PVC consists of long chain polymers with large (high molecular weight) strands of molecules. Plasticizers, such as phthalate esters, are liquids. The processing conditions -- involving heat and sometimes pressure -- force the polymers and the liquids together. In the new state, the liquid acts s an internal lubricant and allows the polymer chains to move relative to each other, i.e., provides flexibility. This material then can be molded or shaped into a variety of useful products.

Where will the average person come into contact with flexible vinyl in their homes?

Many products in the home are made of flexible vinyl. The most common uses, however, are products like flooring; insulation on the wiring and cable that runs through your house or your car; shower curtains; synthetic leathers, such as automotive upholstery; and toys.

Would most flexible vinyl household products contain phthalate esters?

Most soft and flexible vinyl products will contain phthalate esters as a plasticizer.

Does the plasticizer industry believe vinyl is necessary and beneficial?

Very useful products have high demand and become dominant in the market. On the other hand, if a product is not useful it has no market life. PVC is the second largest plastic in the world because it is durable, inexpensive and easily manufactured. In short, PVC provides properties that consumers need.

Why is flexible vinyl different from other plastics?

Flexible vinyl is different from other plastics due to its fabrication process. Other plastics are single grade materials which don't vary appreciably in flexibility, hardness or other properties. The plastic supplied to the processor can be molded or shaped, but the material's characteristics cannot be changed. In contrast, vinyl may start as a rigid plastic, but adding phthalate esters during product manufacture will actually soften the material. This process can achieve a desired level of flexibility or softness.

Quite simply, phthalate esters are unique products that can transform a rigid plastic into a soft and pliable plastic. As a result, the compounds provide an incredible versatility to vinyl.

Are consumers at risk from coming into contact with vinyl products containing phthalates?

Humans come into contact with phthalate esters by using flexible vinyl products. Sitting in a naugahyde^¨ chair, playing with a vinyl beachball or fishing with a favorite vinyl fishing lure are examples of contact with flexible vinyl products. However, limited use of these products does not mean that humans are absorbing the compounds. Exposure to phthalate esters does not mean there is a risk from them. Phthalate esters are among the most widely studied compounds in the world from a toxicity standpoint and have shown no adverse human health effects. Although consumers come into contact with vinyl products and may absorb trace amounts of phthalate esters into their system, scientific evidence has not shown any threat to human health.

It appears that animal testing has shown some phthalates to be carcinogens. Are these compounds a threat to our health?

No, there is not any validated scientific evidence to indicate that phthalate esters pose health problems for humans. Scientific research shows that rodents are uniquely sensitive to phthalate esters. As a result, some phthalates have shown the potential to induce liver or kidney tumors when fed to laboratory animals at high doses for extended periods of time. Adverse liver effects, however, are not seen in other mammals more closely related to humans (i.e., hamsters and monkeys). Humans and other species respond very differently to the ingestion of the materials. In short, extremely high quantities of phthalate esters may pose health problems for rodents, but there is no evidence indicating the compounds pose any health risk for humans at realistic exposure levels. For 25 years these compounds have been researched and tested so they can be used safely. Based on the best evidence to date, we strongly believe phthalates are safe and pose no hazard to children or adults when properly used in vinyl products.

Don't some phthalates cause effects on the liver, such as increased liver weights? Are these known human effects?

Although effects have been observed in the liver of some rodents that have been fed extremely large quantities of phthalate esters, the effects are not considered adverse health effects. The liver of a rodent may increase in size to metabolize and eliminate phthalate esters (a normal biological activity), but the human metabolic system can process this material. For 25 years these compounds have been researched and tested so they can be used safely. Based on the best evidence to date, the Panel strongly believes phthalates are safe and pose no hazard to children or adults when properly used in vinyl products.

How do government agencies establish acceptable levels of exposure for chemicals?

The acceptable daily intake (ADI) levels set by governments is typically based on animal studies. Agencies determine the dose of a compound that caused an effect in animals and then apply safety factors to that (sometimes agencies will take the highest dose that caused no effect and apply safety factors to that). Those safety factors are added to compensate for species differences, age differences and a host of other biological differences. The Phthalate Esters Panel supports government activities to establish scientifically sound ADIs, however, the Panel thinks that the effects seen in rodents, for this particular class of compounds, will not occur in humans.

What is the endocrine disruption hypothesis?

The endocrine disruption hypothesis asserts that exposure to small amounts of some chemicals in the environment may interfere with the endocrine system and lead to harmful effects in humans or wildlife.

Why are phthalates frequently listed as potential endocrine disruptors?

Based on the reproductive effects observed in high-dose studies of phthalate esters, this class of compounds has been included on lists of endocrine disruptors. However, the ability of a compound, at high dose levels, to cause reproductive effects does not indicate that a compound will act as an endocrine disruptor. The Phthalate Esters Panel has tested phthalate esters for possible estrogenic activity and has seen consistently negative results. In addition, phthalate esters have been used for over 40 years and there is no validated scientific evidence that these compounds cause adverse human health effects.

Have the phthalates used in toys been tested for their ability to mimic estrogen?

The principal phthalate used in toys, DINP, has recently been tested for its ability to mimic estrogen in the body. The tests have been conducted in two forms, in vitro (test tube) and in vivo (live animal). Initial research results of in vitro screening tests for DINP have been overwhelmingly negative. More importantly, however, the results of in vivo testing indicated that phthalate esters, including DINP, have no estrogenic effects on the endocrine system at realistic exposure levels.

Is the endocrine disruption hypothesis valid, or simply an extension of chemophobia?

Quite frankly, we do not know. This question underlines the importance of continued investigation of this hypothesis. Because the Phthalate Esters Panel has been studying phthalate esters for a long period of time, the Panel believes it is "ahead of the curve" in understanding the chemical properties and propensities for adverse effects. Chemicals may have an effect on the endocrine system, but this influence could occur in many different ways. For this reason, the Panel has conducted research to determine the estrogenic properties of phthalate esters, and has seen no evidence of adverse effects in live animal tests. There is simply no validated evidence that these compounds act as endocrine disruptors in humans or wildlife at the normally low concentrations found in the environment.

Would the Panel endorse labeling products that contain phthalate esters?

No. Government has a responsibility to understand and interpret scientific data on compounds used in consumer products to protect citizens against hazardous chemicals. The average person may not understand toxicology or be able to accurately determine whether a chemical is hazardous to their health. The Phthalate Esters Panel believes that government should regulate chemicals which harm human health, however, this is not the case with phthalate esters. Scientific evidence has not shown exposure to phthalate esters from vinyl products to cause any human health risk, therefore labeling would simply confuse the public and cause undue alarm.

The toy manufacturers made a pledge in the mid-80s to remove one particular phthalate ester, DEHP, from some of their products. Was this because of a demonstrated risk to children?

No. There was never any validated scientific evidence that indicated threat from phthalate esters used in children's products. Diethylhexylphthalate (DEHP) became a focus of attention after a study in the early 1980s showed adverse health effects in rats and mice. The toy industry removed DEHP until further scientific research could be conducted. Since that time, an extensive amount of subsequent research indicates that these effects are not relevant to humans. Knowing the unique sensitivity of rodents to phthalate esters, the toy industry understands that DEHP never presented a health risk to children. However, from a public perception standpoint, the removal of DEHP from children's products was necessary to maintain consumer confidence in the toy market.

Some organizations are suggesting parents avoid toys with phthalates. Do you agree?

The Phthalate Esters Panel does not think flexible vinyl products pose health risks to children or adults simply because they contain phthalate esters. In fact, the U.S. Environmental Protection Agency (EPA), when asked if parents should try to keep infants and children from playing with or chewing on plastic objects, responded by saying, "At present, EPA does not believe the scientific evidence supports this recommendation."  For twenty-five years these compounds have been researched and tested so they can be used safely. Based on the best evidence to date, the Panel strongly believes phthalates are safe and pose no hazard to children or adults when properly used in vinyl products.

Haven't some European countries banned toys containing phthalates?

In March 1998 the European Commission raised the issue of exposures to phthalates from certain children's products for discussion with European Member States, but based on scientific evidence, the majority found no reason to take regulatory action. The Commission decided to wait until the publication of an in-depth report from a Dutch Consensus Group, which was investigating the use of phthalates in toys.

In the meantime, this highly political and emotional issue has led some countries to make announcements that they intend to impose bans as a precaution. Some countries have notified the Commission of their intent, but no such bans have yet been put in place and the Commission has not given them clearance to do so. Based on the best evidence to date, however, the scientific research does not warrant action of this kind.

What is currently happening with the European Commission on this issue?

The Dutch Consensus Group has since finalized its report on exposure to phthalates from toys which showed, largely, that children are not at risk from these products. The European Commission is now working on an amendment to the existing "Marketing and Use Directive" which would require toy manufacturers to test PVC toys to ensure that safe migration limits are always met. The Phthalate Esters Panel welcomes a standard for toys that is based on sound science. Countries that are currently banning phthalates are not acting in accordance with the scientific evidence.

Is the Consumer Product Safety Commission investigating phthalates in toys?

The U.S. Consumer Product Safety Commission (CPSC), as well as regulatory agencies in Canada and Europe, are reviewing the use of phthalates in toys. In March, CPSC published a preliminary report evaluating these compounds. At that time, the agency found that "commercially available DINP... is not a developmental or reproductive toxin." The agency also committed to further investigating the scientific research on phthalates for its final report which is expected late this fall. The Panel has been working closely with the agencies to provide them with to the extensive database of research associated with phthalates. If the science shows certain products may pose a hazard, the Panel supports steps to eliminate the hazard. To this end, the Panel supports regulatory decisions based on sound science.

Is the American Chemistry Council committing a great many resources to handle public concerns about phthalate esters?

Yes. Many different resources are being deployed to address public concerns because this is a complex issue, and the answers are largely based in science. Moreover, the chemical industry must communicate in terms the public understands. The Phthalate Esters Panel's objective is to effectively communicate the scientific nature of this issue and to maintain public trust in flexible vinyl products containing phthalate esters.

Has ACC increased its dialogue with regulatory agencies about these issues over the last year?

The Phthalate Esters Panel has existed within ACC for 25 years. During its existence the Panel has worked to conduct research and share results with the Food and Drug Administration, Environmental Protection Agency, the Consumer Product Safety Commission and other regulatory agencies. Communication between these groups has been ongoing since the Panel was created. That long history is one reason for the Panel's confidence in these compounds, and its belief in the safety of flexible vinyl products containing phthalate esters.

What are the plasticizer industry views on the use of these compounds?

Plasticizer producers are committed to providing the public with safe compounds -- in raw materials and finished products. For twenty-five years these compounds have been researched and tested so they can be used safely. Based on the best evidence to date, the Panel strongly believes phthalates are safe and pose no hazard to children or adults when properly used in vinyl products. The Panel is committed to continued research and testing of phthalate esters and will work closely with government agencies so that these products can continue to be used safely. The Phthalate Esters Panel enthusiastically endorses flexible vinyl products.