DOCSLIB.ORG

Wastewater Technology Fact Sheet Dechlorination

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Wastewater Technology Fact Sheet Dechlorination United States Office of Water EPA 832-F-00-022 Environmental Protection Washington, D.C. September 2000 Agency Wastewater Technology Fact Sheet Dechlorination DESCRIPTION or total combined chlorine residual remaining after chlorination. Typically, dechlorination is Dechlorination is the process of removing residual accomplished by adding sulfur dioxide or sulfite chlorine from disinfected wastewater prior to salts (i.e., sodium sulfite, sodium bisulfite, or discharge into the environment. Sulfur dioxide is sodium metabisulfite). Carbon adsorption is also an most commonly used for dechlorination and is the effective dechlorination method, but is expensive major focus of this fact sheet. Some dechlorination compared to other methods. Carbon adsorption is alternatives include carbon adsorption, sodium usually implemented when total dechlorination is metabisulfite, sodium bisulfite, and hydrogen desired. peroxide. Sodium metabisulfite and sodium bisulfite are mainly used in small facilities because Specific design criteria and monitoring these materials are more difficult to control requirements for a particular region are determined compared to sulfur dioxide. Hydrogen peroxide is by the state regulatory agency. Typically, the not frequently used because it is dangerous to treatment plant’s National Pollutant Discharge handle (WEF, 1996). Elimination System (NPDES) permit limits effluent chlorine residual and toxicity. Currently, many APPLICABILITY permits require very low or “non-detect” chlorine residuals, making dechlorination critical. Chlorination has been used widely to disinfect wastewater prior to discharge since passage of the One important alternative to dechlorination is to 1972 Federal Water Pollution Control Act achieve disinfection without the use of chlorine. (WPCA), (Finger et al., 1985). In the first years Other means of disinfection, such as ozone or following the WPCA, disinfected wastewater with ultraviolet disinfection, have also become significant levels of residual chlorine was routinely increasingly prevalent (U.S. EPA, 1986; Blatchley, discharged into the receiving waters. It became E.R. III, et al., 1996). clear, however, that residual chlorine is toxic to many kinds of aquatic life (see, for example, ADVANTAGES AND DISADVANTAGES Mattice and Zittel, 1976, and Brungs, 1973). Moreover, the reaction of chlorine with organic Advantages materials in the water formed carcinogenic trihalomethanes and organochlorines (WEF and • Protects aquatic life from toxic effects of ASCE, 1991). As a result, dechlorination was residual chlorine. instituted to remove residual chlorine from wastewater prior to discharge into sensitive aquatic • Prevents formation of harmful chlorinated waters. compounds in drinking water through reaction of residual chlorine with water- Dechlorination minimizes the effect of potentially born organic materials. toxic disinfection byproducts by removing the free -2 -2 - + Disadvantages (1) SO3 + HOCl ÿ SO4 + Cl + H -2 -2 - + • Chemical dechlorination can be difficult to (2) SO3 + NH2Cl + H20 ÿ SO4 + Cl + NH4 control when near zero levels of residual chlorine are required. Since free chlorine and inorganic chloramines react rapidly with S(IV) (Helz, 1998), a short contact • Significant overdosing of sulfite can lead to time of one to five minutes is considered to be sulfate formation, suppressed dissolved sufficient; nevertheless, complete blending at the oxygen content, and lower pH of the point of application is essential for effective finished effluent. dechlorination (WEF and ASCE, 1992). DESIGN CRITERIA Proper dosage is critical to produce a non- detectable chlorine residual. On a mass basis, 0.9 Chemistry of Dechlorination by Sulfonation parts sulfur dioxide (or 1.46 parts NaHSO3 or 1.34 parts Na2S2O5) is required to dechlorinate 1.0 part Sulfur dioxide (SO2) is a corrosive, nonflammable residual chlorine. In practice, approximately a one- gas with a characteristic pungent odor. At to-one ratio is used (WEF, 1996). Dosing in excess atmospheric temperature and pressure, it is a must be avoided because excess sulfite can react colorless vapor. When compressed and cooled, it with dissolved oxygen (four parts sulfite to one part forms a colorless liquid. Sulfur dioxide is supplied oxygen) in the wastewater to produce sulfates, as liquefied gas under pressure in 100 or 150 pound potentially leading to reduced dissolved oxygen containers and one-ton cylinders. As an alternative concentrations and low pH levels in the finished to sulfur dioxide gas, various dry chemicals are effluent for high levels of overdose (WEF, 1996). available which form sulfur dioxide in solution. Careful process control will help prevent These include sodium sulfite (Na2SO3), sodium overdosing. metabisulfite (Na2S2O5), sodium bisulfite (NaHSO3), a 38 percent aqueous solution of sodium Equipment for gaseous sulfonation metabisulfite, and sodium thiosulfate (Na2S2O3), among others (Lind, 1995). Equipment required for gaseous sulfonation using SO2 is similar in design to that used for When dissolved in water, chlorine hydrolyzes to chlorination, except that the materials are chosen form hypochlorous acid (HOCl) and hypochlorite for their application-specific chemical resistance ions (OClG) which, taken together, are referred to as (WEF, 1996). The four basic components of the “free chlorine.” (Free, uncombined chlorine, Cl2, is system include: sufficient gas supply with rarely found in wastewater since the conditions of automatic switch-over between cylinders; a formation are relatively extreme [Lind, 1995]). metering system, usually consisting of a vacuum Once formed, the free chlorine reacts with natural regulator and a rotameter for feed rate control; one organic matter in water and wastewater to form or more injectors with check valves; and a residual chlorinated organic compounds. The free chlorine analyzer to measure and transmit a continuous also combines with ammonia to form mono-, di-, signal proportional to the chlorine residual in the and trichloramines in quantities dependent on the sample stream. ratio of chlorine to ammonia nitrogen (Lind, 1995). In small concentrations, exposure to SO2 can cause When either sulfur dioxide or sulfite salts are eye and throat irritation. In high concentrations, dissolved in water, aqueous sulfur compounds in exposure can produce a suffocating effect caused by the +4 oxidation state are produced, often notated irritation to the upper respiratory tract. Therefore, S(IV) (Helz and Nweke, 1995). The S(IV) species, facility design should include features for safe -2 such as the sulfite ion (SO3 ), reacts with both free storage, handling, and use of sulfur dioxide. The and combined forms of chlorine, as illustrated in chlorine and sulfur dioxide cylinders should be equations (1) and (2) (WEF, 1996): located in separate rooms and stored in a well- ventilated, temperature-controlled area so that their but this suffers from loss of accurate calibration at temperature never drops below 18 or exceeds 70 low concentrations (Finger et al., 1985). Though degrees Celsius. Gas leak detectors are necessary in some sources claim to have developed process the storage area and the sulfonator area. An control methods employing oxidation reduction emergency eyewash shower and self-contained potential (ORP) as an effective stand-in for direct breathing apparatus should also be provided. All chlorine measurement (Bossard et al., 1995), other personnel should receive emergency response sources assert that ORP is an inappropriate training. Facilities with more than 1,000 pounds of technique for this purpose (WEF, 1996). For these SO2 stored on-site must abide by the Process reasons, control of dechlorination—particularly Management Safety Standard in the OSHA dechlorination to zero residual—has been regulations (OSHA, 1998). problematic. Treatment plant operators have had to work around this limitation using various control Effect of Temperature on Gas Withdrawal Rate strategies. The room temperature where the gas supply is One commonly used strategy is the use of a “zero- located should be maintained around 70 degrees F shifted” or “biased” analyzer (WEF, 1996; Nagel, to ensure optimal gas withdrawal rates (WEF, 1994). In this scheme, a residual chlorine analyzer 1996). At this temperature, the maximum safe is used and a known concentration, X, of chlorine sulfur dioxide gas withdrawal rate is approximately is added to the effluent sample to be analyzed. In 2 lb/hr for a 150 lb container, or 25 lb/hr for a ton this technique, the “zero” point is shifted by the container. Higher temperatures are required to value of X, and residual chlorine or sulfur dioxide achieve higher continuous gas withdrawal rates. can be inferred from the result of sample analysis. Strip heaters or liquid baths may be used for this purpose. Two types of control systems are often used for dechlorination (WEF, 1996). A “feed-back” Injector Selection control system can be used at treatment plants that are not required to dechlorinate their effluents to Proper selection of the injector is critical for proper zero levels. With feed-back control, an analyzer system operation. The injector produces a vacuum measures the chlorine residual at a point that draws sulfur dioxide gas through the downstream of the sulfur dioxide addition. This sulfonator. It then mixes the gas with dilution signal, along with flow rate data, is relayed back to water supply and injects the solution into the the sulfonator and the dosage is automatically
Load more

Recommended publications
  • Enhanced Conversion Oflactose to Glycerol by Kluyveromyces Fragilis
    APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Mar. 1989, p. 573-578 Vol. 55, No. 3 0099-2240/89/030573-06$02.00/0 Copyright C) 1989, American Society for Microbiology Enhanced Conversion of Lactose to Glycerol by Kluyveromyces fragilis Utilizing Whey Permeate as a Substrate WHEAMEI JENQ,1 RAY A. SPECKMAN,' RICHARD E. CRANG,2* AND MARVIN P. STEINBERG1 Department of Food Science, 1304 West Pennsylvania Avenue,' and School of Life Sciences, 505 South Goodwin Avenue,2 University ofIllinois, Urbana, Illinois 61801 Received 6 June 1988/Accepted 12 December 1988 Kluyveromycesfragilis (CBS 397) is a nonhalophilic yeast which is capable of lactose utilization from whey permeate and high glycerol production under anaerobic growth conditions. However, the optimum yields of glycerol (11.6 mg/ml of whey permeate medium) obtained in this study occurred only in the presence of 1% Na2SO3 as a steering agent. The use of other concentrations of Na2SO3, as well as 5% NaCl and 1% ascorbic acid, had no or detrimental effects on cell growth, lactose utilization, and glycerol production. Glycerol yields were greater in cultures grown from a light inoculum of K. fragilis than in cultures in which a resuspended mass of cells was introduced into the medium. The results of this study suggest that this strain of K. fragilis may be useful commercially in the utilization of cheese whey lactose and the concomitant production of glycerol. Cheese whey represents a commercial by-product gener- troleum derivatives, which is less expensive than processing ated in such massive quantities that its safe disposal is a by sugar fermentation. major problem for many municipal sewage treatment plants.
    [Show full text]
  • PUBLISHED UNITED STATES COURT of APPEALS for the FOURTH CIRCUIT ZENECA, INCORPORATED, Plaintiff-Appellant, V. DONNA E. SHALALA
    PUBLISHED UNITED STATES COURT OF APPEALS FOR THE FOURTH CIRCUIT ZENECA, INCORPORATED, Plaintiff-Appellant, v. DONNA E. SHALALA, in her official capacity as Secretary of Health and Human Services; JANE HENNEY, M.D., Commissioner of the Food No. 99-2329 and Drug Administration, Defendant-Appellees, v. GENSIA SICOR PHARMACEUTICALS, INCORPORATED, Movant-Appellee. Appeal from the United States District Court for the District of Maryland, at Baltimore. William M. Nickerson, District Judge. (CA-99-307-WMN) Argued: April 5, 2000 Decided: May 17, 2000 Before NIEMEYER, Circuit Judge, HAMILTON, Senior Circuit Judge, and Roger J. MINER, Senior Circuit Judge of the United States Court of Appeals for the Second Circuit, sitting by designation. _________________________________________________________________ Affirmed by published opinion. Senior Judge Hamilton wrote the opinion, in which Judge Niemeyer and Senior Judge Miner joined. COUNSEL Anthony Craig Roth, MORGAN, LEWIS & BOCKIUS, L.L.P., Washington, D.C., for Appellant. Gerald Cooper Kell, Senior Trial Counsel, Office of Consumer Litigation, UNITED STATES DEPARTMENT OF JUSTICE, Washington, D.C., for Appellees Sha- lala and Henney; David Glenn Adams, VENABLE, BAETJER, HOWARD & CIVILETTI, L.L.P., Washington, D.C., for Appellee Gensia Sicor. ON BRIEF: Stephen P. Mahinka, MORGAN, LEWIS & BOCKIUS, L.L.P., Washington, D.C., for Appellant. David W. Ogden, Acting Assistant Attorney General, Office of Consumer Liti- gation, UNITED STATES DEPARTMENT OF JUSTICE, Washing- ton, D.C.; Barbara J. Stradling, Associate Chief Counsel for Enforcement, FOOD AND DRUG ADMINISTRATION, Washing- ton, D.C., for Appellees Shalala and Henney. James N. Czaban, VEN- ABLE, BAETJER, HOWARD & CIVILETTI, L.L.P., Washington, D.C., for Appellee Gensia Sicor.
    [Show full text]
  • Sulfur Safety Data Sheet SDS No: 6192 According to Federal Register / Vol
    Sulfur Safety Data Sheet SDS No: 6192 According To Federal Register / Vol. 77, No. 58 / Monday, March 26, 2012 / Rules And Regulations Revision Date: 10/23/2018 Date of Issue: 08/30/2012 Version: 1.0 SECTION 1: IDENTIFICATION 1.1. Product Identifier Product Form: Mixture Product Name: Sulfur Synonyms: Brimstone, Sulfur 1.2. Intended Use of the Product Hydrogen sulfide may be present in trace quantities (by weight) in molten sulfur but may accumulate to toxic or flammable concentrations in enclosed spaces such as molten sulfur storage pits, tanks, or tanker/railcar headspaces. Hydrogen sulfide is not considered a hazard associated with solid sulfur. 1.3. Name, Address, and Telephone of the Responsible Party Customer Hess Tower 1501 McKinney Houston, TX 77010 T:(713) 496-4000 When calling the main operator ask for the EHS Safety Department. All Hess SDSs are also available via the Hess.com website. 1.4. Emergency Telephone Number Emergency Number : (800) 424-9300 CHEMTREC (24 hours) SECTION 2: HAZARDS IDENTIFICATION 2.1. Classification of the Substance or Mixture GHS-US Classification Flam. Sol. 2 H228 Skin Irrit. 2 H315 Aquatic Acute 2 H401 Comb. Dust Full text of hazard classes and H-statements : see Section 16. 2.2. Label Elements GHS-US Labeling Hazard Pictograms (GHS-US) : GHS02 GHS07 Signal Word (GHS-US) : Warning Hazard Statements (GHS-US) : May form combustible dust concentrations in air. H228 - Flammable solid. H315 - Causes skin irritation. H401 - Toxic to aquatic life. Precautionary Statements (GHS-US) : P210 - Keep away from heat, sparks, open flames, hot surfaces. - No smoking. P240 - Ground/Bond container and receiving equipment.
    [Show full text]
  • On the Cycling of Sulfur and Mercury in the St. Louis River Watershed, Northeastern Minnesota
    Page 1 of 91 Final Report On the Cycling of Sulfur and Mercury in the St. Louis River Watershed, Northeastern Minnesota An Environmental and Natural Trust Fund Final Report August 15, 2012 Michael Berndt and Travis Bavin Minnesota Department of Natural Resources 500 Lafayette Rd. St. Paul, MN 55455 Page 2 of 91 Final Report Contents Summary .......................................................................................................................................... 3 Introduction ..................................................................................................................................... 4 Methods ........................................................................................................................................... 5 Sampling Site Selection ................................................................................................................ 5 Chemical Analysis ......................................................................................................................... 6 34 18 Sulfur and Oxygen Isotopes in Dissolved Sulfate (δ SSO4 and δ OSO4)........................................ 7 Stream Gaging .............................................................................................................................. 7 Results .............................................................................................................................................. 7 Watershed Survey .......................................................................................................................
    [Show full text]
  • Sulfite: Here, There, Everywhere
    Sulfite: Here, There, Everywhere Max T. Baker, PhD Associate Professor Department of Anesthesia University of Iowa Inadvertent Exposures Combustion of fossil fuels, Air pollutant Large quantities as sulfur dioxide are expelled from volcanos Kilauea on the Big Island Small quantities endogenously formed in mammals from sulfur-containing amino acid metabolism Deliberate Exposures As Preservative- Wine, Beer (dates to Roman times From burning sulfur candles) Fruits and Vegetables (reduce browning, extend shelf-life) Pharmaceuticals1 Reductant - Antioxidant - Antimicrobial What are Sulfites? Oxidized Forms of the Sulfur Atom Sulfur Dioxide, MW = 64, bp = - 10oC (gaseous) Sulfur (IV) - Oxidation state of 4 S = Atomic number 16 – electrons/shell, 2,8,6 Sodium Dioxide Readily Hydrates2 Sulfur Carbon Dioxide Dioxide (irritant) H O H2O 2 Sulfurous Unstable Carbonic low acid species acid pH high pH Bisulfite Bicarbonate anion anion Sulfite Carbonate dianion dianion Forms radical Doesn’t form radical Bisulfite Can Combine with SO2 to form Metabisulfite + excess Bisulfite Metabisulfite (disulfite, pyrosulfite) “Sulfite” usually added to drugs as sodium or potassium salts of: Sulfite, Bisulfite, or Metabisulfite Endogenous to Mammals Small quantities formed from sulfur-containing amino acid metabolism - cysteine, methionine3 + - + H2O + 2H + 2 e Sulfite Sulfate Rapidly detoxified by sulfite oxidase (SOX) to form sulfate – a two electron oxidation, molybdenum dependent Two Confirmed Sulfite Toxicities Neurological abnormalities from genetic sulfite oxidase deficiency3 Allergic reactions from exogenous exposure4 Oral, parenteral, inhalational exposure: dermatitis, urticaria, flushing, hypotension, abdominal pain and diarrhea to life- threatening anaphylactic and asthmatic reactions “The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic people." - FDA Prevalence – 3-10% are sulfite sensitive among asthmatic subjects.
    [Show full text]
  • Sodium Chlorite Neutralization
    ® Basic Chemicals Sodium Chlorite Neutralization Introduction that this reaction is exothermic and liberates a If sodium chlorite is spilled or becomes a waste, significant amount of heat (H). it must be disposed of in accordance with local, state, and Federal regulations by a NPDES NaClO2 + 2Na2SO3 2Na2SO4 + NaCl permitted out-fall or in a permitted hazardous 90.45g + 2(126.04g) 2(142.04g) + 58.44g waste treatment, storage, and disposal facility. H = -168 kcal/mole NaClO2 Due to the reactivity of sodium chlorite, neutralization for disposal purposes should be For example, when starting with a 5% NaClO2 avoided whenever possible. Where permitted, solution, the heat generated from this reaction the preferred method for handling sodium could theoretically raise the temperature of the chlorite spills and waste is by dilution, as solution by 81C (146F). Adequate dilution, discussed in the OxyChem Safety Data Sheet thorough mixing and a slow rate of reaction are (SDS) for sodium chlorite in Section 6, important factors in controlling the temperature (Accidental Release Measures). Sodium chlorite increase (T). neutralization procedures must be carried out only by properly trained personnel wearing Procedure appropriate protective equipment. The complete neutralization procedure involves three sequential steps: dilution, chlorite Reaction Considerations reduction, and alkali neutralization. The dilution If a specific situation requires sodium chlorite to step lowers the strength of the sodium chlorite be neutralized, the chlorite must first be reduced solution to 5% or less; the reduction step reacts by a reaction with sodium sulfite. The use of the diluted chlorite solution with sodium sulfite to sodium sulfite is recommended over other produce a sulfate solution, and the neutralization reducing agents such as sodium thiosulfate step reduces the pH of the alkaline sulfate (Na2S2O3), sodium bisulfite (NaHSO3), and solution from approximately 12 to 4-5.
    [Show full text]
  • Reregistration Eligibility Decision (RED) for Inorganic Sulfites
    Reregistration Eligibility Decision – Inorganic Sulfites May 2007 Reregistration Eligibility Decision Inorganic Sulfites Special Review and Reregistration Division Office of Pesticide Programs U.S. Environmental Protection Agency 1801 South Bell Street Arlington, VA 22202 Introduction The Environmental Protection Agency (EPA) has completed its Reregistration Eligibility Decision (RED) for the inorganic sulfites case, which includes the chemicals sulfur dioxide and sodium metabisulfite. This assessment provides information to support the issuance of a Reregistration Eligibility Decision for inorganic sulfites. EPA’s pesticide reregistration process provides for the review of older pesticides (those initially registered prior to November 1984) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to ensure that they meet current scientific and regulatory standards. In this document, EPA presents the results of its review of the potential human health effects of dietary, drinking water and occupational/bystander exposure to inorganic sulfites, as well as its ecological risk findings. Evaluations performed by the World Health Organization (WHO), the International Agency for Research on Cancer (IARC), and the Agency for Toxic Substances and Disease Registry (ATSDR) were relied upon for this assessment, in addition to peer-reviewed evaluations performed by the Cosmetic Ingredient Review (CIR), the Organization for Economic Cooperation and Development-Screening Information Data Set (OECD-SIDS) and from other open literature sources. Based on this assessment, the Agency has determined that products containing sulfur dioxide or sodium metabisulfite are eligible for reregistration provided the necessary label changes are made. As a result of this assessment, one tolerance has been reassessed. I. Use Information The inorganic sulfites reregistration case includes the chemicals sulfur dioxide (CAS No.
    [Show full text]
  • Sodium Chlorite Sulfur Destruction
    ® Basic Chemicals Sodium Chlorite Sulfur Destruction Application Description: Advantages of Sodium Chlorite/Chlorine Reduced sulfur compounds are a broad Dioxide: class of oxy-sulfur compounds, such as = = sulfite (SO3 ) and thiosulfate (S2O3 ), that Chlorine dioxide reacts the most rapidly have an oxidant demand. These and does not form chlorinated organic compounds are found in the waste streams by-products. of the petroleum, steel, paper and most While chlorine is the least expensive chemical industries. Their high oxidant chemical, it cannot be used when demand can cause eutrophication of natural organic compounds are present due to waters and excessive chlorine demand in the formation of chlorinated organic by- wastewaters treated by POTWs (Publicly products. Owned Treatment Works). When chlorine can't be used, hydrogen peroxide has the lowest chemical costs. Chlorine dioxide effectively oxidizes these species to sulfate ions over a broad pH range (5-9). Below a pH of 4, sodium Affected Industries: chlorite may be used without the generation Chemicals, Food, Iron & Steel, Mining, Oil of chlorine dioxide. Since these compounds Refining, Plastics & Rubber, Pulp & Paper, are usually found in mixtures of various Textiles ratios the required chlorine dioxide dosage must be determined for each application. Further Information More detailed information on sodium Alternatives: chlorite applications is available upon Hydrogen peroxide solution is added by request through the OxyChem Technical a chemical dosing pump. Services Department. Call or write to: Chlorine gas is added by a vacuum eductor system, while sodium OxyChem hypochlorite solution is added by a Technical Service Department chemical dosing pump. PO Box 12283 Wichita, Kansas 67277-2283 800-733-1165 Ext.
    [Show full text]
  • Sodium Metabisulfite Hypersensitivity in Urticaria
    Our Dermatology Online Original Article SSodiumodium mmetabisulfietabisulfi ttee hhypersensitivityypersensitivity iinn uurticariarticaria Beata Sadowska, Marlena Sztormowska, Marika Gawinowska, Marta Chelminska Department of Allergology, Allergology and Pneumonology Clinic, Medical University of Gdansk, Smoluchowskiego 17, 80- 214 Gdansk, Poland Corresponding author: Beata Sadowska, MD, E-mail: [email protected] ABSTRACT Background: Sodium metabisulfite is a recognized, but rare, trigger of urticaria, wherein the IgE mechanism has been sporadically proven. The aim of this study was to identify the potential reaction to sodium metabisulfite (MBS) based on a placebo-controlled oral challenge in patients with urticaria and suspected hypersensitivity to food additives. Materials and Methods: A total of 110 adult patients (76 females and 34 males with a mean age of 46 years) were included in the study between 2017 and 2019. All subjects underwent MBS skin prick tests (SPT) and patch tests (PT). Patients with a positive skin test or suspected MBS hypersensitivity were qualified for a placebo-controlled oral challenge (OC). Results: Skin testing was positive in 24 patients: SPT in 20% (n = 22), PT in 5% (n = 6). Out of 64 oral challenges, 13 positive results were obtained. Patients with a positive challenge typed sulfite foods twice as often as a culprit compared to those with a negative OC. Conclusions: In patients with urticaria, both the IgE and non-IgE mechanism of MBS hypersensitivity has been demonstrated. Skin tests with a detailed medical history of potentially guilty foods may be helpful in determining sulfite hypersensitivity. Key words: Sulfites; Sodium metabisulfite; Urticaria; Food additive hypersensitivity INTRODUCTION they are not obliged to disclose the total amount of the substance [5].
    [Show full text]
  • Safety Assessment of Sulfites As Used in Cosmetics
    Safety Assessment of Sulfites as Used in Cosmetics Status: Re-Review for Panel Consideration Release Date: August 22, 2019 Panel Meeting Date: September 16-17, 2019 The 2019 Cosmetic Ingredient Review Expert Panel members are: Chair, Wilma F. Bergfeld, M.D., F.A.C.P.; Donald V. Belsito, M.D.; Curtis D. Klaassen, Ph.D.; Daniel C. Liebler, Ph.D.; James G. Marks, Jr., M.D., Ronald C. Shank, Ph.D.; Thomas J. Slaga, Ph.D.; and Paul W. Snyder, D.V.M., Ph.D. The CIR Executive Director is Bart Heldreth, Ph.D. This safety assessment was prepared by Wilbur Johnson, Jr., Senior Scientific Analyst © Cosmetic Ingredient Review 1620 L Street, NW, Suite 1200 ♢ Washington, DC 20036-4702 ♢ ph 202.331.0651 ♢ fax 202.331.0088 ♢ [email protected] Distributed for Comment Only -- Do Not Cite or Quote Commitment & Credibility since 1976 Memorandum To: CIR Expert Panel Members and Liaisons From: Wilbur Johnson, Jr. Senior Scientific Analyst Date: August 22, 2019 Subject: Re-Review of the Safety Assessment of Sulfites The CIR Expert Panel first reviewed the safety of Sulfites in 2003. The Panel concluded that Ammonium Bisulfite, Ammonium Sulfite, Potassium Metabisulfite, Potassium Sulfite, Sodium Bisulfite, Sodium Metabisulfite, and Sodium Sulfite are safe as used in cosmetic formulations. The original report is included for your use (identified as sulfit092019orig in the pdf). Minutes from the deliberations of the original review are also included (sulfit092019min_orig). Because it has been at least 15 years since the safety assessment was published, in accordance with CIR Procedures, the Panel should consider whether the safety assessment of Sulfites should be reopened.
    [Show full text]
  • DNA Methylation Analysis: Choosing the Right Method
    biology Review DNA Methylation Analysis: Choosing the Right Method Sergey Kurdyukov 1,* and Martyn Bullock 2 Received: 8 July 2015; Accepted: 22 December 2015; Published: 6 January 2016 Academic Editor: Melanie Ehrlich 1 Genomics Core facility, Kolling Institute of Medical Research, University of Sydney, Sydney 2065, Australia 2 Cancer Genetics Laboratory, Kolling Institute of Medical Research, University of Sydney, Sydney 2065, Australia; [email protected] * Correspondence: [email protected]; Tel.: +61-299-264-756 Abstract: In the burgeoning field of epigenetics, there are several methods available to determine the methylation status of DNA samples. However, choosing the method that is best suited to answering a particular biological question still proves to be a difficult task. This review aims to provide biologists, particularly those new to the field of epigenetics, with a simple algorithm to help guide them in the selection of the most appropriate assay to meet their research needs. First of all, we have separated all methods into two categories: those that are used for: (1) the discovery of unknown epigenetic changes; and (2) the assessment of DNA methylation within particular regulatory regions/genes of interest. The techniques are then scrutinized and ranked according to their robustness, high throughput capabilities and cost. This review includes the majority of methods available to date, but with a particular focus on commercially available kits or other simple and straightforward solutions that have proven to be useful. Keywords: DNA methylation; 5-methylcytosine; CpG islands; epigenetics; next generation sequencing 1. Introduction DNA methylation in vertebrates is characterized by the addition of a methyl or hydroxymethyl group to the C5 position of cytosine, which occurs mainly in the context of CG dinucleotides.
    [Show full text]
  • “Inactive” Ingredients in Pharmaceutical Products: Update (Subject Review)
    AMERICAN ACADEMY OF PEDIATRICS Committee on Drugs “Inactive” Ingredients in Pharmaceutical Products: Update (Subject Review) ABSTRACT. Because of an increasing number of re- bronchospasm from antiasthmatic drugs, aspartame- ports of adverse reactions associated with pharmaceutical induced headache and seizures, saccharin-induced excipients, in 1985 the Committee on Drugs issued a cross-sensitivity reactions in children with sulfon- position statement1 recommending that the Food and amide allergy, benzyl alcohol toxicity in neonates Drug Administration mandate labeling of over-the- receiving high-dose continuous infusion with pre- counter and prescription formulations to include a qual- served medications, dye-related cross-reactions in itative list of inactive ingredients. However, labeling of inactive ingredients remains voluntary. Adverse reac- children with aspirin intolerance, lactose-induced di- tions continue to be reported, although some are no arrhea, and propylene glycol-induced hyperosmola- longer considered clinically significant, and other new lity and lactic acidosis. Although many other excipi- reactions have emerged. The original statement, there- ents have been implicated in causing adverse fore, has been updated and its information expanded. reactions, these are the most significant in the pedi- atric population. ABBREVIATIONS. FDA, Food and Drug Administration; MDIs, metered-dose inhalers ANTIASTHMATIC MEDICATIONS It is readily appreciated that some percentage of asthmatic children will develop a “paradoxical” Pharmaceutical products often contain agents that bronchospasm after they inhale their medication. Be- have a variety of purposes, including improvement cause many of these reactions were attributed to of the appearance, bioavailability, stability, and pal- sulfite, which had been highly publicized as a caus- atability of the product. Excipients (substances ative agent, it was often first suspected.
    [Show full text]