Fluoridation Safety Seminar • Jeff Zidek – Thatcher Company
Introduction • The purpose of this presentation is to introduce some important safety facts and other useful information regarding fluoridation. • Some properties of Fluoride • Practical handling of Fluoride • The main health hazards associated with Fluoride
Safety • Safety is the name of the game. • Play by the rules.
Safety Overview • Respect and consider the hazards of the chemical • Consider your personal safety always • Consider the others with whom you are working and their safety • Consider the purpose of the chemical that is being use and know the name of the chemical
Fluorine • Fluorine is a gas. • Fluorine is the thirteenth most abundant element found in the earth’s crust. • Fluorine is always found as a combination of chemicals. • When the compound is dissolved in water the compound dissociates into ions such as table salt. • It is the fluoride ions that we are interested in for public benefit.
Chemical Sources • Fluoride can be found in a solid form in minerals such as fluorspar, cyrolite and apatite. • Due to the dissolving power of water, fluoride is found naturally in all waters. • In general, the deeper the groundwater, the greater the natural concentration of fluoride in the water.
Drinking Water Fluoride Compound Additives • Sodium Fluoride • Sodium Fluorosilicate • Hexafluorosilicic Acid (Hexafluorosilicic Acid) HFS or HFA
Sodium Fluoride • Sodium Fluoride (NaF) is a white, odorless material available as either a powder or in the form of crystals. • Powdered Sodium Fluoride is produced in different densities: • Light grade – Less than 65 pounds per cubic foot • Heavy grade – About 90 pounds per cubic foot.
Sodium Fluorosilicate • Sodium Fluorosilicate (Na2SiF6) • Sodium Fluorosilicate is a white, odorless crystalline powder. • Sodium Fluorosilicate is 98% or greater in purity. • Sodium Fluorosilicate is sold in the same densities as sodium fluoride.
Hexafluorosilicic Acid • Hexafluorosilicic Acid (H2SiF6). • Hexafluorosilicic Acid is a straw-colored, transparent liquid. • Hexafluorosilicic Acid is a 20 to 35 percent solution with a pH of 1.2 • Hexafluorosilicic Acid must be handled with care.
Safety • Fluoride is an extremely safe compound at the 1 ppm level found in water supplies. • Operators may be exposed to higher levels by handling the chemicals. • The use of safety equipment is strongly recommended when handling fluoride compounds or performing maintenance.
Safety Gear for Fluoride Powders • Wear protective clothing • NIOSH/MSHA approved dust respirator • Goggles • Gauntlet neoprene gloves (12” minimum length) • Heavy duty neoprene apron • High top boots
Safety Gear for Fluoride Powders Continued… • Protective clothing should always be worn whenever handling the fluoride powders. • Protective clothing should be stored near the entrance of the area where the fluoride powders are stored. • Avoid wearing the protective clothing into other parts of the water plant.
Handling Bags of Fluoride Powder • Use a knife to open the bags and make a clean cut. • Gently pour the powder into the saturator to raise as little dust as possible and empty the bags completely. • Do not store partially filled bags of powder for later use.
Handling Bags of Fluoride Powder Continued… • Dispose of empty bags and wash your hands immediately after handling the powder/bags. • Never eat, drink or smoke in the area where the fluoride is used or stored.
Dissociation of H2SiF6 • H2SiF6 = 2HF + SiF4(gas) • And SiF4(gas) + 2H2O = 4HF + SiO2(solid) • And SiF4(gas) + 3H2O = 4HF + H2SiO3(acid) • And HF = H + F
Safety Gear for Hexafluorosilicic Acid • Always wear protective clothing. • Gauntlet neoprene gloves (12” minimum length) • Full 8” face shield and/or acid type safety goggles. • Heavy duty acid type neoprene apron • Tall Chemical Resistant Boots • Safety showers should be located.
Safety Gear Continued… • Only Neoprene, PVC and Natural Rubber gloves are acceptable while handling fluorine products. • Latex and Nitrile gloves are not acceptable.
Handling Hexafluorosilicic Acid • Keep the acid off clothes and skin and don’t breathe in the fumes. • Use a transfer pump to move the acid from one container to another.
Handling Hexafluorosilicic Acid Continued… • Dispose of empty acid containers as required by state law. • Wash your hands, equipment and protective clothing after handling Hexafluorosilicic acid. Do this immediately and before you do anything else. • Never eat, drink or smoke in areas where the acid is stored or used.
Spill and Releases • All spills must be handled with care. • Steps to follow in the event of a spill or release. • Isolate the spill area and deny entry. • Stay upwind of the spill • Do not touch or allow anyone to touch the spilled or leaked product.
Spill and Releases Continued… • Use Personal Protective Equipment • Try to stop the source of the leak if it is safe to do so. • Contain the spill so that it will not reach the public ground or surface water. Prevent discharge into sewers and waterways.
Spill and Release Containment • Build a dike around the spill using lime (Ca(OH)2) • Do not use soda ash or caustic as this will form sodium fluorosilicate and sodium fluoride (both of these compounds are regulated as hazardous substances) • Lime will neutralize HFS liquid to form the insoluble calcium fluoride.
Spill and Release Containment Continued… • Lime Neutralization • H2SiF6 + Ca(OH)2 forms CaSiF6 + 2H20 • CaSiF6 + 2Ca(OH)2 forms 3CaF2 + Si02 + 2H2O • 0.4 pounds of lime will neutralize 1 pound of HFS liquid solution
Spill and Release Containment Continued… • DO NOT use metal buckets to recover any HFS acid as it will react readily with metal.
Spill and Release Containment Continued… Spillage HFS Liquid Lime Required 1 pound 0.12 pounds 55 gallons 65 pounds 1 – tote Call HAZMAT Bulk Call HAZMAT Any spills larger than 55 gallons should have a HAZMAT response team
Fluoride Exposure • There are two kinds of toxic exposure • Chronic toxic exposures (large doses of fluoride spread over several years) and • Acute toxic exposures (a single massive dose)
Chronic Toxic Exposure • Low level prolonged exposure (2 to 8 times that of the optimal level) can mottle the enamel of the teeth. • At higher prolonged levels of exposure and fluoride intake, osteosclerosis, calcification of ligaments and tendons, and or vertebrate consolidation can occur.
Acute Toxic Exposure • Acute fluoride poisoning may result from ingestion, inhalation or bodily contact with concentrated fluoride compounds. • Accidental ingestion is quite unlikely and not a lot is known about acute fluoride poisoning by ingestion because it is a very rare occurrence.
Acute Toxic Exposure Continued… • Some Symptoms of acute poisoning • The body will tell us if there has been an overexposure to fluoride: • Overdoses will include: • Vomiting • Stomach Cramps • Muscular Weakness • Difficulty in speaking • Disturbed color vision and thirst
Toxic Exposure • Concentrations of fluoride of 1.0 ppm has been exhaustively studied and firmly established as safe beyond question. • To prevent overexposure, the best safety measure is proper handling of fluoride chemicals.
Fumes from HFS • When fumes become irritating to the nose. • STOP IMMEDIATELY • Apply 3M Full face Respirator with 6006 Multi Gas Vapor Cartridge
Fumes from HFS continued… • HFS is a very unique chemical. • Irritation of the nose is the first sign that a respirator must be donned. • A bloody nose follows the irritation if action is not taken.
First Aid for Acute Toxic Exposure • First aid treatment should be started while waiting for medical help.
First Aid for Air-Borne Fluorides (Nose Bleed) • Move the victim from the exposed area • Keep the victim quiet; • Place the victim in a sitting position, leaning forward if possible; • If leaning forward is not possible; place the victim in a reclining position with the head and shoulders raised
First Aid for Air-Borne Fluorides (Nose Bleed) Cont... • Apply pressure directly by pressing the bleeding nostril toward the midline • Apply a cold compress to the victim’s nose and face. • Insert a small, clean pad of gauze (not absorbent cotton) into the nostrils and apply external pressure. • Obtain medical assistance.
Skin Exposure from HFS • Skin exposure from liquid HFS is more hazardous than breathing the vapors. • When liquid HFS comes in contact with the skin, it feels much like water. • Liquid HFS penetrates the skin quickly, burning the skin and absorbing into tissue. • The pain will become intense, deep if not washed off immediately.
First Aid for Acid Splash • Wash away the chemical with large amounts of water as quickly as possible. • Remove the victims clothing from the affected area and continue washing for at least 5 minutes. • Where skin damage has occurred, cover the burns with a dressing bandage.
First Aid for Acid Splash Continued… • If the eye is involved, immediately begin to wash the eye, eyelid and face. • Hold the eyelid open and wash the eye for at least 15 minutes. • After a thorough washing, cover the eye with a clean, dry protective dressing and hold bandage in place. • Even seemingly minor eye injuries can become serious. • Seek immediate medical assistance for the victim.