{"id":912,"date":"2025-12-27T16:03:33","date_gmt":"2025-12-27T16:03:33","guid":{"rendered":"https:\/\/stwpoison.uk\/?page_id=912"},"modified":"2026-01-20T23:24:22","modified_gmt":"2026-01-20T23:24:22","slug":"its-not-just-fluoride","status":"publish","type":"page","link":"https:\/\/stwpoison.uk\/index.php\/its-not-just-fluoride\/","title":{"rendered":"It&#8217;s not just Fluoride"},"content":{"rendered":"\n<p><strong>Hexafluorosilicic acid<\/strong>&nbsp;(H\u2082SiF\u2086) added by Severn Trent Water is not typically a reagent-grade purified compound, but an industrial byproduct. Therefore, its impurity profile is significant and well-documented.<\/p>\n\n\n\n<p>The impurities originate from its primary production method. Over 90% of the world&#8217;s H\u2082SiF\u2086 comes from the&nbsp;<strong>wet scrubbing<\/strong>&nbsp;of gases produced during the manufacture of phosphate fertilisers.<\/p>\n\n\n\n<p>Here is a breakdown of the key impurities, categorised by their origin:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Primary Co-Product &amp; Major Impurity:&nbsp;<strong>Hydrofluoric Acid (HF)<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Origin:<\/strong>&nbsp;The scrubbing solution often contains excess HF to ensure complete reaction and absorption of silicon tetrafluoride (SiF\u2084) gas.<\/li>\n\n\n\n<li><strong>Impact:<\/strong>&nbsp;This makes commercial hexafluorosilicic acid a mixture of H\u2082SiF\u2086 and HF, increasing its corrosiveness and affecting its stoichiometry.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. Impurities from Phosphate Rock (Most Significant Group)<\/h3>\n\n\n\n<p>The phosphate ore (fluoroapatite) contains many trace elements that are volatilised or entrained during the acidulation process and end up in the scrubber liquor. These are the most regulated and concerning impurities, especially when the acid is used for water fluoridation.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Arsenic (As):<\/strong>&nbsp;The impurity of greatest toxicological concern. Regulatory standards for fluoridation-grade acid set strict limits on arsenic content (e.g., NSF\/ANSI Standard 60).<\/li>\n\n\n\n<li><strong>Heavy Metals:<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Lead (Pb)<\/strong><\/li>\n\n\n\n<li><strong>Cadmium (Cd)<\/strong><\/li>\n\n\n\n<li><strong>Mercury (Hg)<\/strong>&nbsp;&#8211; though levels are often very low due to volatility.<\/li>\n\n\n\n<li><strong>Chromium (Cr)<\/strong><\/li>\n\n\n\n<li><strong>Selenium (Se)<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Radioactive Elements:<\/strong>&nbsp;A less-publicised but naturally occurring category.\n<ul class=\"wp-block-list\">\n<li><strong>Uranium (U) and its decay products (e.g., Radium-226, Radon)<\/strong><\/li>\n\n\n\n<li><strong>Polonium-210<\/strong>&nbsp;(a decay product of uranium present in the rock).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Other Elements from Ore:<\/strong>\n<ul class=\"wp-block-list\">\n<li>Phosphorus (as phosphate, H\u2083PO\u2084)<\/li>\n\n\n\n<li>Calcium, Aluminum, Iron, and other cationic impurities that can form insoluble fluorides.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. Process-Related Impurities<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Sulfuric Acid (H\u2082SO\u2084):<\/strong>&nbsp;Phosphate rock is processed with sulfuric acid. Some sulfuric acid mist or sulfur oxides (SO\u2093) can be carried over into the scrubbers.<\/li>\n\n\n\n<li><strong>Phosphoric Acid (H\u2083PO\u2084):<\/strong>&nbsp;The main product of the fertiliser process. Aerosols and volatile phosphorus compounds can be present.<\/li>\n\n\n\n<li><strong>Particulates\/Silica:<\/strong>&nbsp;Fine dust from the rock.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4. Ionic Impurities in Aqueous Solution<\/h3>\n\n\n\n<p>Commercial H\u2082SiF\u2086 is typically a 20-35% aqueous solution. It contains:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Free Fluoride Ions (F\u207b):<\/strong>&nbsp;From the dissociation of H\u2082SiF\u2086 and any excess HF.<\/li>\n\n\n\n<li><strong>Hexafluorosilicate Ions (SiF\u2086\u00b2\u207b):<\/strong>&nbsp;The primary anion.<\/li>\n\n\n\n<li><strong>Hydronium Ions (H\u2083O\u207a):<\/strong>&nbsp;Making it a strong acid (pH typically &lt; 2).<\/li>\n\n\n\n<li><strong>Sulfate (SO\u2084\u00b2\u207b), Phosphate (PO\u2084\u00b3\u207b), and other anions<\/strong>&nbsp;from process carryover.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Purification for Specific Uses<\/h3>\n\n\n\n<p>The level of impurities tolerated depends on the application:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><strong>Water Fluoridation (the largest use):<\/strong>&nbsp;Must meet stringent standards like&nbsp;<strong>NSF\/ANSI Standard 60<\/strong>, which sets maximum contaminant levels (MCLs) for arsenic, lead, and other heavy metals. Suppliers often pre-treat or source selectively to comply.<\/li>\n\n\n\n<li><strong>Industrial Uses (e.g., aluminum production, steel pickling, concrete hardening, glass etching):<\/strong>&nbsp;Impurity limits are less strict but still specified based on their impact on the final product (e.g., colour of glass, strength of concrete).<\/li>\n\n\n\n<li><strong>Laboratory\/Reagent Grade:<\/strong>&nbsp;Highly purified by multiple distillations or other processes to remove metallic and anionic impurities. This grade is much more expensive.<\/li>\n<\/ol>\n\n\n\n<p><strong>In summary, the primary impurities in commercial hexafluorosilicic acid are:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Excess Hydrofluoric Acid (HF)<\/strong><\/li>\n\n\n\n<li><strong>Toxic heavy metals, most notably Arsenic<\/strong><\/li>\n\n\n\n<li><strong>Radioactive nuclides from the phosphate ore<\/strong><\/li>\n\n\n\n<li><strong>Residual phosphate and sulfate<\/strong><\/li>\n<\/ul>\n\n\n\n<p>The presence of these impurities, particularly arsenic and heavy metals, is the central focus of regulatory oversight and public health debate regarding its use in municipal water fluoridation.<br><br>STW claims that on annual basis they collect thousands of water samples directly from households to monitor the quality of water. <br>However at the end of December 2025 we have checked the water quality at many post codes covered by Severn Trent Water and the results are only from October &#8211; at least 2 months old.<br><br>Is this giving you confidence considering the fact that it happened many times in the past to many water companies to overdose chlorine and other chemicals they add to water?<br><br>For instance according to <a href=\"https:\/\/en.wikipedia.org\/wiki\/Severn_Trent\" data-type=\"link\" data-id=\"https:\/\/en.wikipedia.org\/wiki\/Severn_Trent\" target=\"_blank\" rel=\"noreferrer noopener\">Wikipedia page on STW<\/a> in March 2016 unacceptable high levels of chlorine have been detected in Derbyshire and people were advise not to drink it.<br><br>We don&#8217;t have laboratories at home to check the water every so often to be confident that the water is safe to drink <strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-red-color\">especially when a dangerous poison is being added to it.<\/mark><\/strong><br>Chlorine is one thing but what about a poisonous industrial waste that is added to the water supply on a regular basis? <br>How confident can we be that there are no mistakes?<br>It&#8217;s inconceivable to think that a poison is being added to water but there is no 247 reporting to the public. We reckon they do have some live monitoring systems in place but we don&#8217;t have access to that data. <br><br>These once every 2 months online results may maintain confidence in some people but it does not in others <br>Please imagine there was an overspill of poisonous Hexafluorisicic acid into the water in November 2025: <br>1. the old report from October 2025 would not show the mishap because it is simply an out of date report.<br>2. Would a new report e.g. from January 2026 reveal the mishap? <br>Again it would not because the excessive levels of poison had 2 months to dilute in the water downstream<br><br>We don&#8217;t have the data for the more frequent sampling STW claims it does directly in households.<br><br>As you can imagine it is not and it would not be in the interest of the water company to admit it to face lawsuits and fines.<br><br>Regardless of what happens in the background the online results look solid (like propaganda). <br>If your tea tasted bad on some days or if you got sick would you ever connect it to that poisoning? <br>You would not unless the concentration was high enough to smell it or to cause a burning sensation in the mouth or eyes like in the case of chlorine overspill in Derbyshire. If you add sugar and milk to your beverage this only masks the poisonous odour and taste.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"570\" height=\"357\" src=\"https:\/\/stwpoison.uk\/wp-content\/uploads\/2026\/01\/Smell-coffee.jpg\" alt=\"\" class=\"wp-image-1030\" style=\"width:787px;height:auto\" srcset=\"https:\/\/stwpoison.uk\/wp-content\/uploads\/2026\/01\/Smell-coffee.jpg 570w, https:\/\/stwpoison.uk\/wp-content\/uploads\/2026\/01\/Smell-coffee-300x188.jpg 300w\" sizes=\"auto, (max-width: 570px) 100vw, 570px\" \/><figcaption class=\"wp-element-caption\"><em>If you live in Staffordshire, Nottinghamshire, Warwickshire, parts of Darbyshire etc coffee or tea time is not a pleasant experience any more instead it is breathing <a href=\"https:\/\/stwpoison.uk\/\" data-type=\"page\" data-id=\"444\">Hydrogen Fluoride gas<\/a>.<\/em><\/figcaption><\/figure>\n\n\n\n<p>But if your tongue cannot detect the poison in high concentrations (like in most cases) you will know when asked by a GP to pay an <a href=\"https:\/\/en.wikipedia.org\/wiki\/Oncology\" data-type=\"link\" data-id=\"https:\/\/en.wikipedia.org\/wiki\/Oncology\" target=\"_blank\" rel=\"noreferrer noopener\">oncologist<\/a> a visit.<br><br>I remind you that in 2024 STW has dumped millions of litres of raw sewage into the Severn Trent river. This does not increase our confidence in that business. They cannot handle sewage so how about handling a very corrosive acid that eats through concrete?<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Hexafluorosilicic acid&nbsp;(H\u2082SiF\u2086) added by Severn Trent Water is not typically a reagent-grade purified compound, but an industrial byproduct. Therefore, its impurity profile is significant and well-documented. The impurities originate from its primary production method. Over 90% of the world&#8217;s H\u2082SiF\u2086 comes from the&nbsp;wet scrubbing&nbsp;of gases produced during the manufacture of phosphate fertilisers. Here is a&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-912","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/pages\/912","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/comments?post=912"}],"version-history":[{"count":38,"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/pages\/912\/revisions"}],"predecessor-version":[{"id":1097,"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/pages\/912\/revisions\/1097"}],"wp:attachment":[{"href":"https:\/\/stwpoison.uk\/index.php\/wp-json\/wp\/v2\/media?parent=912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}