What are plasticisers?
A plasticiser is a substance which when added to a material, usually a plastic, produces a product which is flexible, resilient and easier to handle. Since the dawn of civilisation, water has been used to plasticise clay for the production of pottery and clay tablets. Also, lime has been used to promote the easier working of cements. Other early examples of plasticisers include the oils to plasticise pitch for caulking prehistoric boats and neatsfoot oil and sperm oil to soften leather.
In modern applications plasticisers are produced by reacting an alcohol (such as methanol or ethanol) with an acid such as phthalic anhydride, adipic acid, etc. These plasticisers must satisfy more demanding technical and economic requirements which are best met by esters such as phthalates, adipates, trimellitates, etc. Phthalates, due to their technical performance, versatility and cost effectiveness, are the most widely used.
What are phthalates?
What is the difference between high and low phthalates?
What other products, apart from PVC, are phthalates used in?
How many phthalates are used in Europe, and what are the principal ones?
Low phthalates account for less than 11% of the total production, with di-2ethylhexyl phthalate (DEHP, also known as DOP) being the most commonly used.
Are phthalates safe?
Because phthalates are so widely used, they have undergone extensive testing for possible health and environmental effects and are among the most widely researched of all chemical substances. In Europe, the European Commission, the European Chemicals Bureau (ECHA) and EU Member States have undertaken 10-year-long comprehensive scientific assessments of both high and low phthalates under the EU Risk Assessment Regulation.
High phthalates (DINP, DIDP, DPHP, DIUP, and DTDP): Risk assessments showed positive results regarding the safe use of this group of substances. They have all been registered under REACH and do not require any classification for health and environmental effects, nor are they on the Candidate List for Authorisation.
Low phthalates (DEHP, DBP, DIBP and BBP): Risk assessments have led to their classification and labelling as Category 1B Reproductive agents and these four phthalates are now on the REACH Candidate List for Authorisation. They have all been registered under REACH.
Phthalates are found in many household items and some of these items contain more than 50% phthalates. Should this be a cause for concern?
If DEHP is a low phthalate of very high concern, shouldn’t it be banned in medical applications?
DEHP has been registered under the EU’s new Chemicals Legislation REACH and this registration enables the continued manufacturing and use of DEHP. However, because it is classified in as a Substance of Very High Concern (SVHC), its uses beyond January 2015 is subject to an Authorisation.
The use of DEHP in some medical applications is allowed in Europe, but upon an evaluation of possible alternatives, four new plasticisers have been added to the European Pharmacopoeia:
- (Hexamoll® DINCH (cyclohexane 1,2-dicarboxylic acid, diisononyl ester)
- BTHC (butyryl tri-n-hexyl citrate)
- TOTM (tris(2-ethylhexyl) trimellitate)
- DEHT (bis(2-ethylhexyl) terephthalate)
These plasticisers can be used in the production of containers for human blood and blood components; tubing used in sets for the transfusion of blood and blood components; and empty sterile containers of plasticised PVC for human blood and blood components.
Is it true that phthalates can leach out of plastic water and soda bottles?
Isn't the plasticiser industry being complacent and insufficiently responsive in view of all of these issues it faces?
The industry is also fully committed to supporting and, where appropriate, commissioning further scientific research about the potential hazards that phthalates may pose to our health and the environment.
It is very important to emphasize that the presence of flexible PVC particles in house dust does not pose any risks to human health. Plasticisers do not readily migrate or leach into the environment from articles because they are physically bound within the PVC matrix. Even in abraded particles that may be collected in the form of dust, plasticisers would remain tightly bound within the PVC matrix. If this was not the case, flexible PVC would not remain flexible and perform as intended. Essential applications such as wire and cable, where electrical safety is paramount, would crack and break rendering them unusable and potentially unsafe for consumers.
Reports linking exposure to phthalates and asthma are often based on finding a correlation, which does not mean causation.
In addition, recent scientific studies have concluded that household dust does not correlate to human exposure levels, and is not an indicator of indoor air quality1. It is therefore not scientifically sound to conclude that levels in dust equate to exposure and therefore exceed safe limits.
1 H. Fromme et al., “Occurrence of phthalates and musk fragrances in indoor air and dust from apartments and kindergartens in Berlin (Germany), Indoor Air 2003, 1-8. Kerstin Becker et al. “DEHP metabolites in urine of children and DEHP in house dust”. International Journal of Hygiene and Environmental Health 207 (2004); 409-417. Tobias Schripp et al. “Chamber studies on mass-transfer of di(2-ethylhexyl)phthalate (DEHP) and di-n-butylphthalate (DnBP) from emission sources into house dust”, Atmospheric Environment 44 (2010) ECPI Scientific Working Group Report 110301 – “Endocrine Data Evaluation Report” – March 2011
In the past, EU classified low phthalates DBP and DIBP were employed in cosmetics and body care products but are no longer found in articles produced and commercialised in the European Union due to provisions of the European Cosmetics legislation, which prohibits the use of substances classified as carcinogenic, mutagenic or repro-toxic (CMR). Non-classified phthalates are not used in this type of applications.
There is no good evidence that exposure to phthalates or other chemicals contributes to obesity – this is simply scaremongering. Lifestyle factors including diet, exercise, smoking, and alcohol consumption are major factors in determining the health of human populations. There is no robust evidence that the very low levels of exposure to chemicals which typically occurs in consumers is contributing to the disease burden of human populations. In fact the contrary is true and chemicals make a positive contribution to health via the myriad benefits they bring to society such as for example safe and hygienic food as well as in healthcare. Occupational Health and Safety controls are of course very important for people working in the chemical industry where there is potential for significant exposure.