I used to take everything I was told at face value. After years of being mislead and it affecting my health and sanity, I now like to check everything myself - against credible sources like scientific reports, studies, clinical trials and production processes.
When I started to check out silicone, I wasn't entirely happy with what I learnt.
This explanation cuts away a lot of jargon to make more sense to those outside of the scientific professions:
"It is a man-made polymer, but instead of a carbon backbone like plastic, it has a backbone of silicon and oxygen. (Note that Iâm using two different words here: silicone is the polymer and silicon, spelled without the âeâ on the end, is an ingredient in silicone.) Silicon is an element found in silica, i.e., sand, one of the most common materials on earth. However, to make silicone, silicon is extracted from silica (it rarely exists by itself in nature) and passed through hydrocarbons to create a new polymer with an inorganic silicon-oxygen backbone and carbon-based side groups. What that means is that while the silicon might come from a relatively benign and plentiful resource like sand, the hydrocarbons in silicone come from fossil sources like petroleum and natural gas. So silicone is a kind of hybrid material.â (Plastic-Free: How I Kicked the Plastic Habit and How You Can Too, p. 277)
Research Resource: Chemical Migration from Silicones Used in Connection with Food Materials & Articles
Research Conducted by:
Dr Brian Willoughby, Dr Steve Holding, Donna Howells, Dr Martin Forrest
Scientists at the Food Standards Agency; London UK
Date Conducted: 3 March 2005
Results / Findings:
- Siloxanes were found during extraction studies conducted by University of Queensland Australia (fluid silicone studies)
- Evidence of contamination from silicone was found in wine & edible oil food stuffs.
- Materials such as aluminium, platinum, magnesium & calcium were found to have leached into foodstuffs when testing carried out on silicone bake ware.
Edit: This research took me some time to find and in the end I had to purchase a copy for a significant fee. The information contained therein is not publicly available without prior purchase. Within this research they referenced another study, which is named above, as conducted by the University of Queensland. I have referenced that same study in my notes above. The original link to this research is not able to be located.
Resource: Audio Interview - Implant Truth
Obtained from: http://www.implanttruth.jshood.com/experts.html
Overview: âThe guardian of Dow Corningâs much-admired ethics program, tells his employer of 26 years that he can no longer accept its decision to continue selling silicone breast implants and submits his recusal. A recusal means he would have nothing more to do with the product â he would not discuss it or help the company defend itself against criticism. This came after, among other things, Swansonâs wife endured one debilitating illness after another for 17 years â illnesses she believed to be caused by the silicone breast implants manufactured by her husbandâs company.â
Edit: Unfortunately the audio interview quoted above is no longer available on the web, sadly. The quotation provided was taken from the original source however given the original source is not available this information is not really admissible.
Study: Silicone-induced foreign body reaction and lymphadenopathy after temporomandibular joint arthroplasty
Conducted by: M.Franklin Dolwick D.M.D., Ph.D. Professor and Chairman,
Thomas B. Aufdemorte D.D.S. , Assistant Professor
Excerpt: âEight patients with previously placed silicone temporomandibular joint (TMJ) implants were operated on again. Excised tissues from in and around the joint were histologically evaluated. In one case, a parotid lymph node was also examined. All specimens revealed fragmented, amorphous, refractile, but non-birefringent, irregularly spherical foreign material consistent with fragmented silicone. Granulomatous inflammation and multinucleated giant cells were associated with the silicone material. These findings demonstrated that silicone may not be a totally inert material and that its biomechanical properties are not ideal for use in the TMJâ.
Purchased from: http://www.sciencedirect.com/science/article/pii/0030422085900799
Edit: Since the original posting of this article, several more sources have become available. I have listed these with the intention of providing a broader spectrum of information for my readers to make their own informed decisions via.
Study: Heat stability and migration from silicone baking molds
Conducted By: MEUWLY Roger ; BRUNNER Kurt ; FRAGNIERE CÃ©line ; SAGER Fritz ; DUDLER Vincent ;
Excerpt: Translated from French using Google Translate
The thermal stability of silicone molds used in baking was studied using various standard methods. The results of the migration tests using modified polyphenylene oxide of (MPPO, Tenax) as food simulant indicate that these materials are stable up to 150 Â° C. Above this temperature, the value of 10 mg / dm2 recommended by the European Council Resolution is achieved in most cases. The migration residue is mainly composed of cyclic oligomers of linear polydimethylsiloxane but some molds. These oligomers have a weight between 500 and 2100 Dalton with a maximum ranging from 1000 to 1500 Dalton with the test temperature. Loss measurement of volatiles at 200 Â° C complete migration results and shows that some molds lose more than 0.5% of their weight during heating 4 hours. Although mold mass loss decreases rapidly with the number of use, all observations indicate that silicone baking molds are not inert enough for use in all field temperatures announced by the manufacturers.
My take aways: Unsurprisingly, silicone is not proven safe for use at high temperature baking, despite manufacturer claims.
Study: Determination of polydimethylsiloxanes by 1H-NMR in wine and edible oils
Conducted By: K. Mojsiewicz-PieÅkowskaa, Z. JamrÃ³giewicza & J. Åukasiaka
Excerpt: Analytical procedures were developed to permit the determination of PDMS at 0.06 mg kg-1 in wine and at 6 mg kg-1 in edible oils samples using readily available NMR instrumentation. It was, however, possible to lower the limit of detection to 6 Î¼g kg-1 for wine and to 60 Î¼g kg-1 for edible oils using a higher field instrument (500 MHz). Relative standard deviations (Sr) were obtained for wine (0.028) and for oil samples (0.043), which when compared with values obtained for samples spiked with PDMS (0.021) indicated that the sample preparation was the main factor determining the precision of the method. The average recovery rates for PDMS were 97 and 95% for wine and edible oils, respectively. PDMS was detected in four brands of Italian wine, with Chianti-Rafaello containing the highest concentration (0.35 mg kg-1), and in four types of edible oils, highest concentration (11.9 mg kg-1) being found in Italian corn oil. None of the levels of PDMS found in the food samples exceeded the permissible standards laid down by the Codex Alimentarius Commission (10 mg kg-1), with the exception of the one corn oil sample.
My take aways: Whilst this does not provide details as to the preparation of samples, it does advise that there is leachate. It also advises that leachate is in line with what is considered acceptable by the Codex Alimentarius Commission. I am not now nor have I ever been a fan of the work of the Codex Alimentarius Commission so that to me is of little comfort.
Study: Migration of Siloxane Oligomers in Foodstuffs from Silicone Baking Moulds
Conducted By: Ruediger Hellinga, Katja Kutschbachb & Thomas Joachim Simat
Excerpt: Various foodstuffs were prepared in silicone baking moulds and analyzed for siloxane migration using a previously developed and validated 1H-NMR method. Meat loaf significantly exceeded the overall migration limit of 60 mg kgâ1 (10 mg sdmâ1) in the first and third experiment. The highest siloxane migration found in a meat loaf after preparation in a commercial mould was 177 mg kgâ1. In contrast, milk-based food showed very low or non-detectable migration (<2.4 mg kgâ1), even containing high fat levels. Similar results were achieved using 50% ethanol as the simulant for milk-based products, as defined in the Plastics Directive 2007/19/EEC. After solvent extraction of the moulds in simulating long-term usage, no further migration into the food was detectable, indicating that there is no significant formation of low molecular weight, potentially migrating siloxanes from the elastomer. During repeated usage, the moulds showed a high uptake of fat: up to 8.0 g fat per kg elastomer. Proper tempering of the moulds had a major influence on the migration properties of siloxanes into different foodstuffs. Non-tempered moulds with a high level of volatile organic compounds (1.1%) were shown to have considerably higher migration than the equivalent tempered moulds.
My take aways: Silicone bakeware once again in this study was proven to leach during baking. The amount of leachate varied depending on how or whether the molds were tempered.
Testing Framework for Silicone: Multiple testing of food contact materials: A predictive algorithm for assessing the global migration from silicone moulds
- a. Department of Analytical and Environmental Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- b. Belgian Packaging Institute, Z.1. Researchpark 280, 1731 Zellik, Belgium
Outline: For reasons of food safety, packaging and food contact materials must be submitted to migration tests. Testing of silicone moulds is often very laborious, since three replicate tests are required to decide about their compliancy. This paper presents a general modelling framework to predict the sample's compliance or non-compliance using results of the first two migration tests. It compares the outcomes of models with multiple continuous predictors with a class of models involving latent and dummy variables. The model's prediction ability was tested using cross and external validations, i.e. model revalidation each time a new measurement set became available. At the overall migration limit of 10 mg dmâÂ², the relative uncertainty on a prediction was estimated to be â¼10%. Taking the default values for Î± and Î² equal to 0.05, the maximum value that can be predicted for sample compliance was therefore 7 mg dmâ2. Beyond this limit the risk for false compliant results increases significantly, and a third migration test should be performed. The result of this latter test defines the sample's compliance or non-compliance. Propositions for compliancy control inspired by the current dioxin control strategy are discussed.
My takeaways: This is NOT a study. This is an outline of the testing frame work use for silicone leachate tests. Its interesting if you want to get into how silicone is actually tested. It does state clearly that silicone testing is laborious and requires a three-phase process which could explain why so many products that have been manufactured are now being shown to be insufficient or not up to manufacturer claims.
Case Study: Characterisation and migration properties of silicone materials during typical long-term commercial and household use applications: a combined case study
Details: R. Hellinga*, P. Seifriedb, D. Fritzscheb & T.J. Simatb - Pages 1489-1500
Abstract: The main question was whether a significant degradation or even breakdown of the silicone elastomer could take place yielding enhanced migration of dimethyl siloxanes. Oligomeric dimethyl siloxanes are reaction side-products of the polymerisation process and despite their origin as so-called non-intentionally added substances (NIAS) were found to be the by far most dominating constituents of the overall migration. Furthermore, the influence of long-term thermal stress on the functionality of the elastomer was proven. Migration into food was determined by 1H-NMR and was found to decrease during the experiment from values between 11 and 18âmgâkgâ1 to levels below the limit of detection (LODâ<â1âmgâkgâ1). No formation of migrating siloxanes beside the initial amount in the new, unused moulds could be observed. The loss of extractable siloxanes of the used compared with the new moulds was compensated by an uptake of fat and other lipophilic food constituents. The release of volatile organic compounds (VOC) decreased from 0.44% for the new moulds to 0.14% for the longest used ones (about 1700 individual uses; the corresponding summarised baking time was approximately 400âh at 180Â°C). GC-MS analysis of evaporating volatile compounds showed only cyclic oligomers for the new moulds but exclusively incorporated food components for the heavily used moulds. The physical properties of the silicone moulds remained almost constant during the experiment; no limitations in function due to the repeated thermal stress were observed. Similar results were obtained for baby teats under household conditions of use: a 100 times repeated simulated use in contact with milk followed by subsequent microwave sterilisation did not influence the function or mechanical properties. Because milk is only a weak extracting agent no significant changes in the amount of extractable siloxanes between new and used teats could was seen. Again an uptake of fat was seen and the amount of VOC decreased from 0.26% to 0.17%.
My takeaways: Yes there is leachate from silicone - particularly new products though it is apparently in line with what is considered acceptable.
Research: Determination of siloxanes in silicone products and potential migration to milk, formula and liquid simulants
Conducted By: Kai Zhanga*, Jon W. Wonga, Timothy H. Begleya, Douglas G. Haywarda & William Limma Pages 1311-1321
Abstract: A pressurised solvent extraction procedure coupled with a gas chromatographyâmass spectrometryâselective ion monitoring (GCâMSâSIM) method was developed to determine three cyclic siloxanes, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6) and three linear siloxanes, octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5), in silicone products. Additionally, two different extraction methods were developed to measure these siloxanes migrating into milk, infant formula and liquid simulants (50 and 95% ethanol in water). The limits of quantification (LOQs) of the six siloxanes ranged from 6âng/g (L3) to 15âng/g (D6). Silicone nipples and silicone bakewares were extracted using pressurised solvent extraction (PSE) and analysed using the GCâMSâSIM method. No linear siloxanes were detected in the silicone nipple samples analysed. The three cyclic siloxanes (D4, D5 and D6) were detected in all silicone nipple samples with concentrations ranging from 0.5 to 269âÂµg/g. In the bakeware samples, except for L3, the other five siloxanes were detected with concentrations ranging from 0.2âÂµg/g (L4) to 7030âÂµg/g (D6). To investigate the potential migration of the six siloxanes from silicone nipples to milk and infant formula, a liquid extraction and dispersive clean-up procedure was developed for the two matrices. The procedure used a mix of hexane and ethyl acetate (1â:â1, v/v) as extraction solvent and C18 powder as the dispersive clean-up sorbent. For the liquid simulants, extraction of the siloxanes was achieved using hexane without any salting out or clean-up procedures. The recoveries of the six siloxanes from the milk, infant formula and simulants fortified at 50, 100, 200, 500 and 1000âÂµg/l ranged from 70 to 120% with a relative standard derivation (RSD) of less than 15% (nâ=â4). Migration tests were performed by exposing milk, infant formula and the liquid simulants to silicone baking sheets with known concentrations of the six siloxanes at 40Â°C. No siloxanes were detected in milk or infant formula after 6âh of direct contact with the silicone baking sheet plaques, indicating insignificant migration of the siloxanes to milk or infant formula. Migration tests in the two simulants lasted up to 72âh and the three cyclic siloxanes were detected in 50% ethanol after an 8-h exposure and after 2âh in 95% ethanol. The highest detected concentrations of D4, D5 and D6 were 42, 36 and 155âng/ml, respectively, indicating very limited migration of D4, D5 or D6 into the two simulants.
My takeaways: This study is quite in depth. They determined 6 substances that occur within silicone, then used two different extraction methods to determine if silicone teats leach when feeding babies formula or milk products.
Based on these exhaustive tests, it appears that little to no silicone leachate occurs with baby feeding teats, in this study. Its important to note that, with everything (science included) what you seek is what you find and therefore this is not a totally conclusive result as others study indicate there is leachate.
It appears that the word âsafeâ instead of meaning âprotected from or not exposed to danger or risk; not likely to be harmed or lostâ now simply is taken to mean ânot proven to be UN-safeâ.
Edit: My beef here is not with silicone per se. It is a very versatile substance and has been successfully used in a variety of applications. My concern is with product manufacturers. It seems they have free reign to create a product, label it and not have any studies or testing to adequately confirm its safety. That is my issue.
You may be wondering now âwell, what am I supposed to use to feed my child? What about dummies? What about toys?â There is another option you may like to consider - natural rubber.
It is important to note that there are two types of rubber products on the market; natural rubber and latex rubber. Some children have been found to be allergic to LATEX rubber which has been found to contain PVC components and isn't ideal for feeding with.
I havenât found anything to confirm allergic responses to pure ORGANIC natural rubber however, if your child is sensitive, may I suggest a skin prick test to confirm any allergic responses before re-purchasing new teats & dummies.
You can purchase an Allergy Testing Kit to conduct tests at home if that is easier for you - great for very sensitive children with continued allergic responses.
NB: It is important to note that the bodyâs allergic reaction is a physiological response to external stimulus. Adrenal glands & gut health are the major factors in allergic responses from children. Gut health should be examined by a health care practitioner experienced in gut health and immunity to determine causes of continued allergic responses. If you treat the cause effectively, your child may suffer fewer allergies over the course of their life.
My baby girl loves it & grinned as soon as I gave it to her.
That, to me, is all I need to know. Sheâs happy with it, Iâm happy sheâs safer with it & weâre all happy campers here in Eco Mama Land.
Edit: Whilst we did use all natural rubber teats and dummies for our first born daughter, we acknowledge that rubber can be a cause of severe allergic reactions in some children. Overall, silicone appears to be the safer option for these children however one can now make a more informed decision, realising that nothing is totally inert - even glass and stainless steel.
Worth thinking about... and worth switching about :)
Lots of love,
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