Hypo Products - Erowid · OxyChem ® emphasizes caution ... caustic soda, as a raw material. Sodium Hypophosphite ... Hypo Products Handbook Hypophosphorous Acid. …

Specialty Business Group

Responsible CareA Public Commitment

Hypo ProductsHandbook

Sodium Hypophosphite

Hypophosphorous Acid

Manganese Hypophosphite

SPE-HYPO-HB 05/00

Important: The information presented herein, while not guaranteed, was prepared by technicalpersonnel and is true and accurate to the best of our knowledge. No warranty or guarantee, expressor implied, is made regarding performance, stability or otherwise. This information is not intended tobe all-inclusive as the manner and conditions of use, handling, storage and other factors may involveother or additional safety or performance considerations. While our technical personnel will be happyto respond to questions regarding safe handling and use procedures, safe handling and use remainsthe responsibility of the customer. No suggestions for use are intended as, and nothing herein shallbe construed as a recommendation to infringe any existing patents or to violate any Federal, State orlocal laws.

Occidental Chemical CorporationSpecialty Business GroupOccidental Tower5005 LBJ FreewayDallas, Texas 75244800/752-5151

Occidental Chemical Corporation

Foreword

This handbook provides basic safety and handling information to those who buy, use, and handle thethree Hypo Products marketed by Occidental Chemical Corporation: Sodium Hypophosphite, Hypo-phosphorous Acid (Hypo Acid) and Manganese Hypophosphite. OxyChem® emphasizes caution andproper care in handling these products and invites inquiries to its Technical Service group prior to theactual use of these chemicals. Anyone using these products should be thoroughly familiar with theproper handling and storage requirements. Those looking to install a new handling system may be as-sisted by the information in the following pages. Those who already handle these products can use theinformation presented here to properly maintain equipment and to train personnel who will be respon-sible for working with these products. This handbook intends to present the most widely accepted andsafest storage and handling practices used by the chemical industry today. However, handling proce-dures and problems necessarily vary with the equipment, facilities and physical plant characteristics ofeach location. The handler and/or user is best qualified to determine what methods are appropriate totheir operation to ensure safe handling and use practices.

OxyChem can provide additional assistance to those who may require more information than is con-tained in this book. OxyChem maintains a staff of trained engineers and technologists at its TechnicalCenter in Niagara Falls, New York. To obtain additional literature or assistance, contact your nearestOxyChem Sales Office.

For 24 hour Emergency Assistance call

800-733-3665 [or] 972-404-3228

OxyChem Technical Service (8 AM - 5 PM EST)

800-733-1165 [or] 716-278-7201E-Mail: [email protected]

Hypo Products Handbook

Table of ContentsPage

Introduction...................................................................................................................................... 1Properties and Specifications.......................................................................................................... 2

Table 1 - Summary of Hypo Product Specifications........................................................... 2Table 2 - Typical Properties of the Hypo Products............................................................. 3

Manufacturing ................................................................................................................................. 4Sodium Hypophosphite ...................................................................................................... 4Hypophosphorous Acid ...................................................................................................... 4Manganese Hypophosphite................................................................................................ 5

Applications ..................................................................................................................................... 6Receiving Shipments ...................................................................................................................... 8

Labeling Information........................................................................................................... 8Methods of Shipment ......................................................................................................... 8

Hypo Products Storage & Handling................................................................................................. 9Product Storage .................................................................................................................10Shelf Life ............................................................................................................................10Hypo Acid Drum Transfers.................................................................................................11Materials of Construction ...................................................................................................11Equipment Construction.....................................................................................................12Cleaning & Disposal of Empty Drums................................................................................14

Safety Precautions ..........................................................................................................................15Flammability .......................................................................................................................15Reactivity............................................................................................................................15Employee Training .............................................................................................................15Vapor Exposure Limits .......................................................................................................16Protective Equipment .........................................................................................................16Effects of Overexposure ....................................................................................................16Routes of Exposure............................................................................................................17First Aid ..............................................................................................................................17

Emergency Response Program ......................................................................................................18Emergency Assistance.......................................................................................................18Spill Response Plan ...........................................................................................................18Reporting Requirements ....................................................................................................19Waste Disposal ..................................................................................................................19


Mission StatementOxyChem ManufacturingIn support of OxyChem’s mission, the manufac-turing organization will provide quality productsand services of ever increasing value at the low-est possible costs to satisfy the needs of ourcustomers.

Our objective is to provide customers with along-term supply of competitively priced prod-ucts. Based upon our vertical product integra-tion, focus on cost effective management andapplication of quality principles, OxyChem’s goalis to be the preferred long-term supplier to ourcustomers.

The protection of the environment and the healthand safety of our employees, customers, and thecommunities in which we operate or transportproducts through, is our highest priority. We willbuild trust through open communication aboutour operations and our commitment to Respon-sible Care® which enhances our position as apreferred supplier.

Responsible Care®

A Public CommitmentAs a member of the Chemical ManufacturersAssociation (CMA), Occidental Chemical Corpo-ration is committed to support a continuing effortto improve the industry’s responsible manage-ment of chemicals. We pledge to manage ourbusiness according to these principles:• To recognize and respond to community con-

cerns about chemicals and our operations.• To develop and produce chemicals that can

be manufactured, transported, used and dis-posed of safely.

• To make health, safety and environmentalconsiderations a priority in our planning for allexisting and new products and processes.

• To report promptly to officials, employees,customers and the public, information onchemical related health or environmentalhazards and to recommend protective meas-ures.

• To counsel customers on the safe use, trans-portation and disposal of chemical products.

• To operate our plants and facilities in a man-ner that protects the environment and thehealth and safety of our employees and thepublic.

• To extend knowledge by conducting or sup-porting research on the health, safety and en-vironmental effects of our products, proc-esses and waste materials.

• To work with others to resolve problems cre-ated by past handling and disposal of hazard-ous substances.

• To participate with government and others increating responsible laws, regulations andstandards to safeguard the community, work-place and environment.

• To promote the principles and practices ofResponsible Care by sharing experiencesand offering assistance to others who pro-duce, handle, use, transport and dispose ofchemicals.


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IntroductionOccidental Chemical Corporation manufactures three inorganic hypophosphite based products that willbe referred to in this handbook as the “Hypo Products.” They are shown below along with theirchemical formulations and alternative names by which they may be referred.

Product Name & Formulation Chemical & Common Names • Sodium Hypophosphite • Phosphinic Acid, Sodium Salt, Monohydrate

NaH2PO2 • H2O • Sodium Phosphinate Monohydrate

• Hypophosphorous Acid • Phosphinic AcidH3PO2 • Hypophosphorous Acid

• Manganese Hypophosphite • Phosphinic Acid, Mn+2 Salt (2:1) MonohydrateMn(H2PO2) 2 • H2O • Manganese Hypophosphite-1-Hydrate: metal salt

In this handbook the properties, chemistry, handling and applications of these Hypo Products will bediscussed. All three products are manufactured at our ISO 9002 certified facility in Niagara Falls, NYand have been commercially available for many years. Quality of product, safe on time delivery, andcustomer attention are the elements of product differentiation, which are emphasized by OxyChem.Good quality and high assay are important factors in reducing side reactions or undesired effects, whileefficient deliveries are an essential part of a quality manufacturing operation. OxyChem technical peo-ple would be pleased to discuss the chemistry of these products and to offer suggestions concerningapplications and safe handling.


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Properties and SpecificationsOccidental Chemical’s Sodium and Manganese Hypophosphite products are both in powder form andhave little or no odor. Hypophosphorous Acid comes as a 50% solution. This solution a moderatelystrong monobasic acid with strong but slow reducing action and should be handled accordingly. Safetyand handling instructions should be followed closely to protect people, equipment and the environment.

Table 1

Summary of Hypo Product Specifications

Sodium Hypophosphorous ManganeseHypophosphite Acid 50% Hypophosphite

Chemical Formula NaH2PO2 • H2O H3PO2 Mn(H2PO2)2 • H2O Appearance - Clear, water- Pink granular crystal

white soln or powder

Assay 98% min.† 50.0 – 52.0% 97% min.102 - 105%††* (H3PO2 total acidity)

Total Water - - 10.7% max.**

Odor None† - - Color, APHA - 30 max. - Specific Gravity (25°C) - 1.210 – 1.265 - Arsenic (as As2O3), ppm 1 max. (as As) - 10 max.

Iron (Fe), ppm 2 max.†† 3 max. 35 max.

Lead (Pb), ppm 1 max.†† - 20 max. Heavy Metals (as Pb) 2 ppm max. - -

Phosphate (PO4) Passes NFX Test† - 0.10% max.

Phosphite (as Na2HPO3) 0.5% max.†† - -

Calcium (Ca) Passes NFX Test† - 0.05% max.50 ppm††

Carbonate (as CO3) - - Nil - NFX Test

† NFX Grade†† Electroless Nickel Grade * The product is over-dried to prevent caking. The assay calculation is based on monohydrate.** Includes approximately 9% water of hydration.Appropriate test procedures and Certificates of Analyses (COA) for the Hypo Products are available uponrequest from OxyChem’s Technical Service Department.


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Table 2

Typical Properties of the Hypo ProductsSodium Hypophosphorous ManganeseHypophosphite Acid 50% Hypophosphite

Chemical Formula NaH2PO2 • H2O H3PO2 Mn(H2PO2)2 • H2O

Molecular Weight 106 66.00 202.93

CAS Number 10039-56-2 (monohydrate) 6303-21-5 10043-84-2 7681-53-0 (anhydrous salt)

Primary Application Electroless Nickel Color Stabilizer or Nylon fiberPlating Polymerization Catalyst production

Appearance White Crystal Clear Liquid Pink Crystal

Odor Odorless Odorless/faint acidic Odorless

Specific Gravity @ 25°C 0.88 packed 1.250 1.2 packed0.78 loose

Bulk Density @ 25°C, (lb/ft3) 49 - 55 76.5 75 packed(lb/gal) N/A 10.2 N/A

Vapor Density N/A N/A N/A

Melting Point (°C/°F) N/A -25/-13 N/A

Boiling Point (°C/°F) N/A 108/226 N/A

Decomposition Temp (°C/°F) >285/545 <108/226 >350/662

Dehydrates at (°C/°F) 100/212 100/212 150/302

Flash Point (COC) None None None

Autoignition Temperature None None None

Solubility in Water @ 25°C 100% Infinite 12.5%

Enthalpy of Solution ~0.86 KCal/lb - -(endothermic)

pH 6-8 (50% soln) 0.78 (50% soln) 4.4 (1% soln)

Ionization Constant - 8.0 x 10-2 (pK = 1.1) -

Vapor Pressure, mm Hg @ 25°C N/A 18.7 N/A@ 50°C 72.7@ 80°C 279.1

Viscosity, centipoise @ 20°C N/A 8.0 N/Acentipoise @ 60°C 5.7

N/A = Not Applicable


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ManufacturingThe three Hypo Products are a classical case of vertical integration. Manganese Hypophosphite is pro-duced from a reaction involving Hypophosphorous Acid, which is made from OxyChem’s Sodium Hy-pophosphite, and this requires one of our basic chemicals, caustic soda, as a raw material.

Sodium HypophosphiteThe production of Sodium Hypophosphite does not have a clear-cut stoichiometric balance, but in-volves the following basic chemistry:

P4 + NaOH + H2O + Ca(OH)2 → NaH2PO2 + PH3 + CaHPO3 + H2

Elemental Caustic Water Slaked Sodium Phosphine Calcium HydrogenPhosphorous Soda Lime Hypophosphite Gas Phosphite Gas

The Sodium Hypophosphite produced by this reaction is then dried and crystallized, while the phos-phine gas is burned to generate Phosphoric Acid (H3PO4).

Hypophosphorous AcidThere are three traditional technologies used for commercially produced Hypophosphorous Acid. Al-though there are other potential processes that involve phosphine or calcium hypophosphite and oxalicacid, they are of lesser importance due to their high cost or poor product quality. The chemistry of thethree traditional routes is depicted as follows:

1) Hydrochloric Acid Route

NaH2PO2 + HCl (aq) (vac./evap.)→ H3PO2 + NaClSodium Muriatic Hypophosphorous Sodium

Hypophosphite Acid Acid Chloride (Salt)

2) Sulfuric Acid Route

2 NaH2PO2 + H2SO4 + x H2O → 2 H3PO2 + Na2SO4 •x H2OSodium Hypo Sulfuric Acid Water Hypo Acid Sodium Sulfate


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Hypophosphorous Acid (continued)

3) Ion Exchange RouteFirst Ion Removal:

NaH2PO2 + Resin • H+ → H3PO2 + Resin • Na+

Sodium Hypo Hypo Acid

Then Ion Regeneration:

Resin • Na+ + H2SO4 or HCl → Resin • H+ + Na2SO4 or NaClSulfuric or Muriatic Sodium or Salt

Acids Sulfate

Manganese HypophosphiteManganese Hypophosphite is produced through the introduction of manganese metal to a 50% solu-tion of Hypophosphorous Acid.

2 H3PO2 + Mn → Mn(H2PO2)2 • H2O + H2

Hypo Manganese Manganese HydrogenAcid Metal Hypophosphite Gas

The Manganese Hypophosphite produced by this reaction is then dried, crystallized, and filtered priorto packaging.


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ApplicationsSodium Hypophosphite

Electroless Nickel - A critical ingredient used in Electroless Nickel (EN) Plating solutions. Inthe same manner electric current supplies electrons in the electrolyticprocess, Sodium Hypophosphite acts as a reducing agent to supply theelectrons necessary to the EN process. Phosphorous content of the ENalloy deposit is also supplied by this hypophosphite component. The ENprocess allows for uniform plating thickness on not only metal objects,but also plastics and ceramics.

Chemical Intermediate - Used as a raw material in the production of other products, including Hy-pophosphorous Acid. It may be used in synthetic organic chemistry, es-pecially in deamination via reduction of diazo derivatives.

Reducing Agent - May be used as a reducing agent or antioxidant in chemical processing.

Analytical Reagent - The NFX Grade has use as an analytical reagent.

Polymerization Catalyst - May be used as a catalyst in some polymerization reactions.

Polymer Stabilizer - May be used as a stabilizer to prevent degradation of polymers duringextrusion or in other heated processing.

Fire Retardant - May be used as a partial fire retardant.

Ion Exchange Resin - May be used as a source of electrons in resin regeneration.

Manganese HypophosphiteNylon Fibers - Critical role in the manufacture of nylon carpet fibers. Improves fiber’s

UV stability and dye color fastness.

Pharmaceuticals - Primary chemical intermediate for the production of various products.

Chemical Intermediate - Used in the preparation of certain linear condensation polymers.


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Hypophosphorous AcidBleaching Agent - Used as a bleaching or decolorizing agent for plastics, synthetic fibers

(primarily polyester) and chemicals.

Color Stabilizer - Used as a decolorizing agent and for color stabilization during the manu-facture of chemicals and several plastics, including: nylon fibers, polyam-ides, polyester fiber, polyacrilonitrile, alkyd resins, epoxies, fatty acid es-ters, and glycerols.

- Also used to prevent color in copper descaling.

Hypophosphite Salts - Used in the production of Hypophosphite Salts, (i.e., Calcium, Magne-sium, Manganese, Potassium, Iron and Ammonium) which are in turnused in synthetic fibers as: wetting, dispersing, emulsifying and anti-staticagents.

Chemical Intermediate - Used in organic synthesis and organo phosphinic acid production.

Neutralizing Agent - Used as a moderately strong monobasic acid.

Catalyst - Used as a polymerization and polycondensation catalyst.

Wetting Agent - Used as a wetting, dispersing, or emulsifying agent in electroplating.

Reducing Agent - May be used for its strong but slow reducing action.

Antioxidant - May be used as an antioxidant.

Pharmaceutical - May be used as a stimulant in pharmaceuticals.


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Receiving ShipmentsAll Department of Transportation (DOT), Envi-ronmental Protection Agency (EPA) and Occu-pational Safety and Health Administration(OSHA) rules and regulations should be re-viewed before handling the Hypo Products. Allregulations must be followed and should be in-corporated into your written unloading and han-dling procedures. State and local authoritiesshould be contacted to ensure that a facilitymeets all regional requirements. All employeeshandling these products should receive propertraining, be familiar with the appropriate MaterialSafety Data Sheets (MSDS) and applicableregulations.

Storage facilities must be designed to minimizehuman and environmental exposure to indus-trial chemicals. When appropriate, personalprotective equipment must be used by properlytrained employees. A safety shower and eyewash station should be readily available. (Alsoreference the “Safety Precautions” section ofthis manual.)

Labeling InformationInformation required on the package labels maybe found in the last section of OxyChem’s cor-responding Material Safety Data Sheet.

Methods of ShipmentThe Hypo Products are available from Oxy-Chem in the following package sizes:

Sodium HypophosphiteFiber Drums: (non-returnable, poly-lined)

Net Wt. Gross Wt. * 50 lb. (23 Kg) 56 lb. (25 Kg)† 55 lb. (25 Kg) 61 lb. (28 Kg)110 lb. (50 Kg) 117 lb. (53 Kg)300 lb. (136 Kg) 313 lb. (142 Kg)400 lb. (181 Kg) 416 lb. (189 Kg)

* NFX Grade (All others are for Electroless Nickel Grade)† Also available in 55 lb. paper bags.

Bulk Bags: (Woven polypropylene, PE-lined)

Net Wt. Capacity 1,100 lb. (500 Kg) 25 cu. ft.2,000 lb. (907 Kg) 47 cu. ft.

Hypophosphorous AcidHDPE Plastic Drums: (non-returnable)

Net Wt. Gross Wt. Gallons150 lb. (68 Kg) 158 lb. (71.7 Kg) 14.7484 lb. (220 Kg) 507 lb. (230 Kg) 47.6

Manganese HypophosphitePlastic Pails or Poly-lined Fiber Drums:

Net Wt. Gross Wt. 50 lb. (22.7 Kg) 53.4 lb (24.2 Kg)100 lb. (45.4 Kg) 106.4 lb. (48.3 Kg)

All these packages are considered as one-wayand non-returnable. Once empty, they shouldbe disposed of properly and should not be re-used.

Based on the demand for these products, theyare not currently available in bulk quantities.


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Hypo Products Storage & Handling 1) Only responsible, well-trained and well-

supervised employees should be entrustedwith the unloading and handling of chemi-cals. A worker should be present whileproduct is being transferred and operationsshould proceed only during daytime orwhen adequate lighting is available. A writ-ten copy of handling procedures should bereadily available.

2) The employees responsible for chemicalhandling should be knowledgeable of theproducts they handle, their potential haz-ards and what precautions are to be taken.They must adhere to appropriate safetypractices.

3) Operations involving any industrial chemi-cals should be designed to minimize workerexposure.

4) All operations should be conducted with noemission of fumes, liquid, or dust. However,because of possible accidental emissions,workers responsible for product handlingshould exercise extreme care and wearproper safety equipment. For liquid prod-ucts this should include, but is not limited to:chemical splash goggles, hard hat, faceshield, NIOSH/MSHA approved respirator,acid type rainsuit, rubber gloves and rubberboots. For products in a powder form, thisshould include: safety glasses, hard hat,NIOSH/MSHA approved dust respirator,rubber gloves and safety shoes. Keep otherpersonnel away from the area unless theyare wearing safety equipment.

5) Avoid chemical contact with the body. Ifcontacted, wash thoroughly with largequantities of cool water and consult a physi-cian. For corrosive materials, such as Hy-pophosphorous Acid, a safety shower andeyewash must be readily accessible andshould be tested regularly. Those locatedoutdoors should be designed for all yearservice. Thermostatically controlled electricheat tracing is preferred for safety showers.Steam tracing should be avoided due to the

potential danger of overheating the showerwater. Visualize an escape route for your-self in the event of an incident and locateany remote shut-off valves or switches.

6) Spill control equipment must be availableand personnel should be trained to handleboth large and small spills. If a spill occurs:

- Protect yourself from injury- Try to stop or minimize the spill- Warn others of the danger area- Notify emergency response personnel for proper cleanup- Notify appropriate authorities

7) Keep heat, sparks, open flames, pilot lights,and lighted cigarettes away from areaswhere the Hypo Products are used sincetoxic, corrosive and explosive gases maybe formed. No smoking or flames should bepermitted in any chemical work areas.

8) Avoid spills or splashing. Open containerscarefully to avoid spurting. Clean up spillsimmediately and dispose of in accordancewith all federal, state and local regulations.

9) Do not add water directly to Hypophospho-rous Acid. If dilution is desired, slowly addacid to water. Avoid inadvertent mixing withalkalis such as caustic soda, or contact withmetals that may cause a possible violentreaction.

10) Before any repairs on acid handling equip-ment are attempted, tanks, pipes, valves,etc., should be drained and purged withwater. The hazard of a hydrogen explosionis present when cutting into empty acid linesor empty tanks. Forcing a stream of N2,CO2 or other inert gas into the line mayminimize this hazard.

11) Once the Hypo Product containers areempty, they should be cleaned out thor-oughly and rendered useless. Do not reusecontainers for other purpose as productresidue may still remain.


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Product StorageStore the Hypo Products in a cool, dry, fire re-sistant area separate from oxidizing agents andaway from direct heat and sunlight. Containersshould be kept tightly closed when not in use.

Appropriate material identification and warninglabels should be clearly visible on storagetanks, piping, valves and containers used inconnection with these materials. Storage facili-ties must be designed to minimize human andenvironmental exposure to the Hypo Productsand their fumes or dust. When appropriate,personal protective equipment, safety showerand eye wash station must be readily availableand used by properly trained employees.

Sodium & Manganese HypophosphiteSodium and Manganese Hypophosphite areboth hygroscopic and must be stored away fromsources of moisture. Absorption of moisture willcause these products to clump, thus causinghandling problems. In the case of Sodium Hy-pophosphite, OxyChem deliberately drives offsome of the water of hydration from the mono-hydrate crystal (NaH2PO2 • H2O) in order to helpcombat this potential problem.

In addition, these two products should not bestored near heat sources that could raise theproduct temperature near 100°C (212°F).These temperatures will cause the products todehydrate, generating steam pressure.

Most customers use Sodium and ManganeseHypophosphite directly from the drum or bulkbag. However, if the customer wants to storethese products in a bin or silo, we recommendthat a dry nitrogen pad be used. It is also rec-ommended that a vibrator(s) be installed on thedischarge cone of the bin to assist in productflow.

Hypophosphorous AcidHandling and storage equipment for Hypophos-phorous Acid service should be designed foracid resistance.

Primary or secondary containment is desirablearound the storage areas to hold any spilledproduct. It should be designed to prevent prod-uct from entering surface or ground water in theevent of a container failure. A preferred dikingarrangement incorporates a leak-proof concretedike equipped with an acid resistant liner. Thisarrangement will not only prevent contaminationof the environment, but also allow for possiblerecovery of the spilled product rather than goingfor disposal. All dikes around liquid productsshould be dead-ended and isolated from sew-ers.

Shelf LifeAs with any product, the shelf life of the HypoProducts is partially dependent on how they arehandled and stored. However, if sealed in theiroriginal containers and stored indoors in a cool,dry area, with minimal temperature fluctuations,separate from oxidizing agents (which are in-compatible) and away from direct heat and sunlight, these products should be expected tohave a shelf life of at least a year from the shipdate.

Although the Hypo Products should be chemi-cally stable for an indefinite time, it is generallyrecommended that all chemical storage adhereto a FIFO (First-In, First-Out) inventory practiceto avoid long term storage. If moisture gets intothe Sodium and Manganese Hypophosphitecontainers, these products tend to clump andmay eventually create handling difficulties.

Note: Do not subject containers of Hypophos-phorous Acid to heat conditions which mightresult in concentrations greater than 50%H3PO2 (evaporation of water). Concentrationsgreater than 50% can yield thermally unstablesolutions.


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Hypo Acid Drum TransfersDrum bungs should be cracked open and thenunscrewed carefully to avoid damage to clo-sures and to prevent the possible eruption ofproduct in the rare case where a drum is underpressure. Pressure should never be used todischarge the contents of a drum. Durable fit-tings should be specified in designing drumemptying systems. Hard piping is recom-mended when feasible.

Three methods are commonly used to emptydrums: gravity flow, pumping, and pulling theproduct into a reduced pressure tank. If the feedtank or reactor can be placed under a slightvacuum, transfer by this last method would bepreferred. Here the drum contents can easily beremoved by inserting a plastic dip tube into thedrum and allowing the product to be sucked intothe receiver. If gravity flow is to be used, liftingand tilting devices will be needed to facilitate theoperation. Pumping, on the other hand, requiresthe investment in a reliable pump and thenthorough cleaning after transfers are complete.The pump’s wetted surfaces should be acidresistant.

Materials of ConstructionThe information provided below has been as-sembled from a variety of sources. Althoughvery limited test conditions existed in some in-stances, this information is intended to providedirection when determining the appropriatematerials of construction (MOC) for handling theHypo Products. However, the materials sug-gested below should not be considered as allinclusive and the following comments are of-fered only as a guideline. When designing asystem to handle the Hypo Products, additionaltesting with specific parameters is recom-mended.

Sodium & Manganese HypophosphiteSodium and Manganese Hypophosphite in theirdry crystalline form are relatively non-corrosive.Stainless steel, glass, Teflon and several otherplastics may be used.

For solutions of these two products, low carbon316L stainless steel or polypropylene are gen-erally sufficient. Fiberglass reinforced plastic(FRP) - Hetron 197 has been used successfullyat ambient temperatures.

Carbon steel is NOT recommended.

Hypophosphorous AcidHypophosphorous Acid is a clear corrosive liq-uid, with a 50% solution having a pH of <1. Atambient temperatures, 316L stainless steel orglass lined carbon steel have provided goodservice life.

Polypropylene (PP), polyethylene (PE) and chlo-rinated polyvinyl chloride (CPVC) are generallythe preferred plastics for use in Hypo Acidservice. Polyvinyl chloride (PVC) is not recom-mended, favoring the above mentioned materi-als and due to insufficient data to accuratelypredict its service life.

Note: Acid concentrations and temperature, aswell as the quality of construction and design,all have an effect on a product’s service life.


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Note: The following information came from aninternal study and is intended to show the rela-tive chemical resistance for several plastics andmetals. More extensive dynamic testing is re-quired in order to accurately determine theiractual expected service life. It is also importantto note that acid concentration and temperaturewill greatly effect the corrosion rate and durabil-ity for any material of construction.

Hypo Acid with PlasticsFor 15% acid at 45°C, polypropylene (PP),polyethylene (PE) and chlorinated polyvinylchloride (CPVC) are superior to polyvinyl chlo-ride (PVC), and are listed in order of prefer-ence.

Acrylonitrile butadiene styrene (ABS) exhibitedexcessive weight gain, while vinyl ester fiberreinforced plastic (VE-FRP) contaminated theproduct. Both of these materials should be ex-cluded from consideration.

At a 30% acid concentration and 50°C, PP andPE offer the best chemical resistance, whileCPVC appears to be suitable. PVC absorbs toomuch acid, which would allow permeation whenunder pressure and cause it to lose strength.More rapid absorption and permeation will oc-cur at lower (vs. higher) acid concentrations.ABS also gave poor performance.

For 50% acid under boiling conditions (108°C),all the aforementioned plastics showed somedistortion (and also discoloration for a few) ex-cept for VE-FRP, which appeared unaffected.

Hypo Acid with MetalsAt a 50% acid concentration under boiling con-ditions (108°C), an austenitic stainless steel(UNS #NO8367) showed no sign of attack dur-ing a 22 day study. The corrosion rate was de-termined to be 2.6 and 4.0 mils/year for the va-por and liquid phases, respectively.

Some degree of corrosion was observed withNickel (N200), Monel (M400) and StainlessSteel (both 310 and 316), and they would notgenerally be recommended at this elevatedtemperature.

Equipment ConstructionStorage Tanks (Hypo Acid only)Passivated 316L (low carbon) stainless steelhas been found to be adequate for the storageof Hypophosphorous Acid at ambient tempera-tures. However, the material can become activeand the corrosion rate would increase at ele-vated temperatures or if the surface is me-chanically disturbed to the extent that the baremetal surface is exposed.

High-density (high molecular weight) cross-linked polyethylene (HDPE) can also be usedfor vertical tank construction. Although thesetanks cannot take pressure and are generallysmall, they are corrosion resistant. Polyethylenetanks should be inspected on a yearly basis.Note: OxyChem’s Hypo Acid product drums areconstructed of blow-molded HDPE.

Rigid PipingLow carbon 316L stainless steel piping is gen-erally used for the Hypo Products at ambienttemperatures (includes solutions of Sodium andManganese Hypophosphite). Polypropylene andCPVC piping have also been used in 50% hypoacid service. Transfer lines should have asshort a run as possible and be made of 2 inchflanged piping. They should be well an-chored/braced and sloped at least 6 inches per100 feet for complete drainage. Flanged pipelends itself to easy maintenance in the event ofa leak from a line or in case an in-line valve hasto be replaced. Any auxiliary rigid piping under 2inch diameter which carries liquid should bethreaded and the threads taped with Teflontape. In the event the transfer lines have to belong and/or run into a maze of other piping, ma-chinery or buildings, they should be taggedand/or color-coded and show flow direction.

A manufacturer of fiberglass reinforced plastic(FRP) piping reports that their material is com-patible with Hypo Acid, but the actual serviceconditions are unknown. (Reference: FibercastCompany, P.O. Box 968, Sand Springs, OK94063, Phone: 800/331-4406 or 918/245-6651).

All piping should be visually inspected for leakson a daily basis. All leaks should be repaired as


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soon as possible. Rigid piping should have athorough annual inspection.Flexible Piping (Hoses)When transferring solutions of the Hypo Prod-ucts, it is occasionally convenient to use someform of flexible hose. Those made of 316stainless steel or Teflon (TFE) type lining aregenerally recommended.

Flexible piping should be inspected for signs ofdeterioration every time it is used. Pressure testeach hose section at least once a year. Do notallow hoses to be stored or used in a positionwhere the recommended bend radius is ex-ceeded.

PumpsSmall drum pumps and diaphragm pumpsmade of 316 stainless steel have been used forthe transfer of Hypophosphorous Acid out ofdrums. Pumping in the process is often servicedby magnetic driven sealless or self-primingcentrifugal pumps with 316 stainless steel orTeflon lined wetted parts for acid resistant.Sealed pumps may use either Teflon impreg-nated asbestos packing material or a mechani-cal seal. Crane Type 9 mechanical seals madewith a 316 stainless steel cage, ceramic seatand graphite seal have been used in the past.

Probably the most serious problem with chemi-cal pumps, particularly those in service withstrong corrosive liquids like Hypo Acid, is theenvironmental and safety issues created byleakage from the stuffing box or mechanicalshaft seal. As a result, magnetic driven seallesspumps with their dependable leak-free servicehave gained tremendous popularity for in-process transfers. Your specific operating con-ditions should be determined before consultinga pump manufacturer.

Note: Pumps should never be throttled on thesuction side. Escaping fumes from pump sealswill cause corrosion and become a mainte-nance nuisance. Therefore, all pumps shouldbe visually examined for leaks on a daily basisand inspected more thoroughly on a yearly ba-sis.

ValvesDurco or Xomox type plugcock valves with a316 stainless steel body and Teflon seat aregenerally recommended for Hypo Acid. Variousother types, such as ball valves, can also beused, but less elaborate fittings are the mostsatisfactory.

All valves should be visually inspected for leakson a daily basis and a detailed inspection per-formed at least yearly.

GasketsEnvelope type gaskets made of Teflon (TFE)are recommended for vessel closures. Flangesshould use a Teflon type gasket.

Meters & GaugesMost standard meters and gauges having acidresistant construction are adequate for use withthe Hypo Products. Brooks type flow meterswith 316 stainless steel bodies and glass tubeshave been used successfully.

Fume Scrubbers & Dust CollectorsFume scrubbers are not generally required withthe Hypo Products; however, one operated oneither water or a weak alkaline solution shouldbe used as necessary.

A dust collector may be required when handlingSodium and Manganese Hypophosphite. Ascrubber operating with water will also work toremove these dusts, although collecting it on adry basis may be advantageous for disposal.Local applicable air pollution control regulationsmay prescribe the type and design of controlsystems and/or operating requirements.

Recommended InspectionEquipment should be thoroughly inspected onan annual basis or as necessary.

Whenever chemical handling equipment is be-ing used, i.e., pumps, flanges, valves etc., it isgood practice to visually inspect them for leaks.Parts of the process that are most susceptibleto loss of integrity should be inspected on aprescheduled basis. Bolted connections that aresubject to vibration, relaxation, or deteriorationshould be checked for tightness every sixmonths or less.


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Cleaning of Empty DrumsThe first step in any drum cleaning procedure isto remove as much product as possible fromthe drum. This is generally simple with drums orpails containing powdered crystalline productssuch as Sodium or Manganese Hypophosphite.In the case of liquids, however, this means theleg of the drum pump or the wand used to drawmaterial from the drum must extend down to thebottom rim of the tilted drum. When an upendeddrum is emptied by gravity, 100 to 200 ml ofliquid will typically remain.

Because a small amount of product may remainin "empty" drums, each container or inner linershould be rinsed until the rinse solution hasminimal residue. Water is generally used for thispurpose, although in the case of Hypophos-phorous Acid, a sodium bicarbonate solutionmay be preferred.

Prior to drum cleaning, be certain that the op-erator wears appropriate protective clothing anda face shield. In addition, the area should beprovided with good ventilation or the proceduredone outdoors.

During the cleaning process, any material thatcannot be used or chemically reprocessedshould be disposed of in a manner meeting allgovernment regulations. Disposal should be in alicensed landfill or treatment facility. In somecases, the waste may be neutralized on site anddeemed as non-hazardous. Further assistancemay be obtained by contacting an approvedchemical disposal service.

Drums previously containing a corrosive liquidmay be placed upside-down in an enclosureover a nozzle that protrudes into the 2 inch bungopening. A drain carries the rinse water to astorage tank for reuse or to a treatment system.Fumes collected in the enclosure are vented toa scrubber. A variation of this method is tomaintain the drum in an upright position. Therinse water or sodium bicarbonate solution isthen introduced into the empty drum through the¾ inch opening via a wand equipped with aspray-nozzle. The 2 inch bung opening shouldbe vented to a scrubber. Once filled, storing thedrums for a few hours will help insure that all

product in drum crevices will be removed. If de-sired, additional drums could then be cleanedby pumping the rinse solution from one druminto another. In the case of Hypo Acid, this maycontinue until the pH of the sodium bicarbonatesolution approaches neutral. After the initial al-kaline rinse, each drum should be rinsed atleast twice with fresh water to remove any tracematerial.

Collect and dispose of all rinse water in accor-dance with all Federal, State and Local regula-tions.

Disposal of Empty DrumsOnce the Hypo Product containers are emptyand cleaned, they should be rendered useless.Do not reuse containers as product residue maystill remain. All labeled precautions must be ob-served. Empty drums are normally crushed orcut up and any polyethylene liners are sliced torender them useless. They may then be dis-posed of as solid waste in a secure landfill orincinerated. If landfilled, make sure that thewaste hauler and disposal site operator are fullyinformed of the operation. In addition, contactyour state and local authorities to determine ifmore stringent regulations apply in your area.Some states require specific waste classifica-tions and record keeping for empty containers.

The plastic Hypophosphorous Acid drums mayalso be recycled. There are organizations thatcan provide drum disposal/recycle assistance.The SPI is one such organization which may beable to identify drum disposal or reconditioningcompanies in your area that handle plasticdrums.

Another organization is the Reusable IndustrialPackaging Association. They has established aprogram to respond to today's strict standardsof environmental responsibility. This trade groupfor the United States and Canada can provide adirectory of reconditioners and may be reachedat:

Reusable Industrial Packaging AssociationPhone: 800/533-DRUMWeb site: http://reusablepackaging.org/


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Safety PrecautionsFlammabilityUnusual Fire & Explosion Hazards:OxyChem’s Hypo Products are classified asnonflammable. However, when in contact withmetals, Hypophosphorous Acid can break downto liberate phosphine and flammable hydrogengas. DO NOT allow the use of open flames,open lights, matches or smoking in or aroundareas where the Hypo Products are handled.

At high temperatures or under fire conditions,the Hypo Products will decompose to generatetoxic and irritating gases, such as phosphine,oxides of phosphorous and acidic residues. So-lutions of Hypophosphorous Acid may becomeunstable upon evaporation of water resulting inconcentrations above 50% H3PO2.

Extinguishing Media:Use water spray, fog, foam, dry chemicals, CO2or other reagents as may be appropriate formaterials in the surrounding fire. Water may beused to cool the product containers.

Special Fire Fighting Precautions:Use self-contained, positive pressure breathingapparatus and full protective equipment.

ReactivityAll three Hypo Products are reducing agents andif uncontrolled, will react violently with strongoxidizing agents such as chromic acid, and evenexplosively with nitrates and chlorates.

The Hypo Products are not combustible but yieldtoxic fumes when heated to decomposition. Atelevated temperatures, Sodium Hypo (>545°F)and Manganese Hypo (>662°F) can violentlydecompose, liberating toxic and flammablephosphine gas. They will also react in hot alkalisolutions (>110°C) to form phosphine.

The maximum recommended temperature forHypophosphorous Acid is 50°C. It should not be

exposed to heat conditions that might result inconcentrations above 50% H3PO2 as this canyield thermally unstable solutions.

Hypo Acid is strongly acidic. When in contactwith metals, it will start to break down consider-ably below its boiling temperature. Phosphineand flammable hydrogen are liberated andphosphorus and phosphonic acids are formed.

Employee TrainingSafe handling of the Hypo Products depends agreat deal on the effectiveness of employeeeducation, proper training in safe practices, theuse of safety equipment and good supervision.Training classes and drills for both new and vet-eran employees should be conducted at leastannually to maintain a high degree of safetyawareness in handling procedures. Employeesshould be informed of the potential hazards thatmay result from improper handling practices.They should be cautioned to prevent spills andthoroughly instructed in emergency spill re-sponse plans in the event that an incident shouldoccur. Employee training and drills should in-clude (but not limited to) the following:

1. The location, purpose and use of fire fightingequipment.

2. The location, purpose and use of personalprotective equipment.

3. The location of safety shower and eye wash.4. Instructions to avoid the inhalation of vapors/

dust and direct contact with these products.5. Instructions to properly report all cases of

equipment failure.6. Procedural instructions on the company’s

Spill Response Plan.7. The location of appropriate Material Safety

Data Sheets (MSDS). Review their content sothe information is understood.


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Vapor Exposure LimitsAt the time of this writing, exposure limits for the Hypo Products have not been established by eitherthe ACGIHa or OSHAb. (Refer to a current OxyChem MSDS for updates.) However, work areas shouldbe well ventilated to minimize worker exposure to potentially hazardous conditions. Provide good gen-eral room ventilation plus local exhaust at points of potential emission. Personnel handling the HypoProducts must be trained and provided with protective equipment to limit exposure. Exposure monitor-ing for Hypophosphorous Acid should follow NIOSH Analytical Method Number 7903 for inorganic ac-ids. As a point of reference, the ACGIH has set a recommended TWAc exposure limit of 1 mg/m3 andSTELd of 3 mg/m3 for phosphoric acid.

a ACGIH – American Conference of Governmental Industrial Hygienists (1999), 1330 Kemper Meadow Drive, Cincinnati, OH 45240-1634b OSHA – Occupational Safety and Health Administration: Refer to current Exposure Standards (29 CFR, Part 1910.1000)c TWA – Time Weighted Averaged STEL – Short Term Exposure Limit

Protective EquipmentRespirator: Use a NIOSH/MSHA approved respirator following manufacturer's recommen-

dation where airborne contaminants may occur.

Eye Protection: Face shield and chemical splash-proof goggles should be worn where appropri-ate to protect against Hypophosphorous Acid splashing (ANSI Z87.1). Safetyglasses with side shields or goggles are generally adequate when handling So-dium and Manganese Hypophosphite.

Gloves: Wear protective gloves such as rubber, neoprene, or vinyl.

Other Clothing: Impervious or chemical resistant clothing and rubber shoes or boots should beused when handling Hypophosphorous Acid. The use of coveralls is suggestedfor Sodium and Manganese Hypophosphite.

Other Equipment: Emergency shower and eyewash facilities should be readily accessible in accor-dance with ANSI Z358.1.

Effects of OverexposureSodium & ManganeseHypophosphite Hypophosphorous Acid

Acute: May cause irritation of theskin, eyes, respiratory anddigestive tracts. Not highlytoxic if swallowed.

Hypophosphorous Acid is a strong acid with cor-rosive properties. Exposure to liquid, mist orfumes may cause irritation and corrosion to theskin, eyes, respiratory and digestive tracts.

Chronic: No known effects. No known chronic health effects.


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Routes of ExposureEyes: Exposure to dust from Sodium or Manganese Hypophosphite may cause moderate

irritation of the eyes, while contact with Hypophosphorous Acid liquid or fumes maycause irritation or burns.

Skin: Exposure to Sodium or Manganese Hypophosphite may cause moderate irritation ofthe skin, while contact with Hypo Acid liquid or fumes may also cause burns.

Inhalation: Inhalation of Sodium or Manganese Hypophosphite dust may cause irritation of therespiratory tract, while inhalation of Hypophosphorous Acid mist or fumes may alsocause burns.

Ingestion: Sodium and Manganese Hypophosphite are not highly toxic if swallowed and areexcreted unchanged in the urine. They may cause irritation to the mouth and gas-trointestinal tract. Hypophosphorous Acid ingestion may cause irritation and/or burnsto the mouth and gastrointestinal tract.

First AidEyes: The object is to flush material out immediately, then seek medical attention. Imme-

diately flush eyes with large amounts of water for at least 15 minutes, forcibly holdinglids apart to ensure complete irrigation of all eye and lid tissue. For Hypophospho-rous Acid, washing eyes within one minute is essential to achieve maximum effec-tiveness. Seek medical attention immediately thereafter.

Skin: Seek medical attention immediately. Flush thoroughly with cool water under showerwhile removing contaminated clothing and footwear. Continue to flush until medicalattention arrives. Discard non-rubber shoes. Wash clothing before reuse.

Inhalation: Remove to fresh air as quickly as possible; if breathing is difficult, have trained per-son administer oxygen. If respiration stops, give mouth-to-mouth resuscitation. Getmedical attention immediately.

Ingestion: Never give anything by mouth to an unconscious person. Give large quantities ofwater or if available, several glasses of milk. Seek immediate medical attention.• If Hypophosphorous Acid is swallowed, Do Not Induce Vomiting.

If vomiting occurs spontaneously, keep airway clear and give more water.

• If Sodium or Manganese Hypophosphite are swallowed, Induce Vomitingby having patient tickle back of throat with finger. Keep airway clear.

**** IMPORTANT ****Assistance should be given to anyone that has been exposed. These first aid procedures must beperformed immediately to gain their full effectiveness. When significant exposure occurs, seek pro-fessional medical treatment immediately after the first aid. Refer to the proper MSDS before han-dling any chemical and take the appropriate safety steps.

Seek Medical Attention Immediately for any over exposure.


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Emergency Response ProgramDue to its corrosive characteristics, users of Hy-pophosphorous Acid are subject to EmergencyResponse requirements under OSHA. AlthoughSodium and Manganese Hypophosphite are notsubject to these same requirements, every com-pany dealing with chemicals should develop andmaintain such a written program. Each employeeshould be thoroughly trained in this program ona regular basis. Such a program should address,but is not limited to the following:

• SAFETY AWARENESS- Communication & employee training- Inspection of premises & equipment- Stock rotation

• PLANNING- Form a HAZMAT Team- Team coordination- Practice and revise until system works

• RELEASE (or) INCIDENT- Evacuate and avoid contact in all forms- Implement your Spill Response Plan- Address Post-Emergency cleanup

• EVALUATION- Upgrade safety program- Medical surveillance

• EMERGENCY ASSISTANCE

OxyChem 24 hr Emergency cus-tomer assistance:

800-733-3665or

972-404-3228

In cases of TransportationEmergencies, call CHEMTREC:

1-800-424-9300

Spill Response PlanGeneral• Keep Recovery/Over Pack drums on hand for

spill cleanups or to enclose leaking drums.• Evacuate - Keep unnecessary people away

and upwind of the spill area.• Do an evaluation from a safe position. Con-

sider factors: quantity, location, weather.• All responding personnel should be equipped

with appropriate protective equipment. For ad-ditional information on safe handling, refer tothe appropriate OxyChem MSDS.

• Once the emergency is addressed, notifyproper authorities and supply complete ap-praisal of the situation.

Sodium & Manganese Hypophosphite• In the case of dry powder type products,

sweep and scoop up all spilled product andother contaminated material, and place inmarked disposal containers.

• If possible, clean up spill on a dry basis andthen flush the area with plenty of water.

• That product which cannot be reclaimed orchemically reprocessed should be disposed ofin a licensed landfill in accordance with fed-eral, state and local regulations.

Hypophosphorous Acid• For a liquid, minimize the spill by shutting off

pumps and valves, invert leaking drums.• Isolate or contain spill/release in as small an

area as possible. Prevent flow to sewers andstreams.

• Neutralize small spills with soda ash, thentransfer into marked containers for disposal ina licensed landfill or treatment facility.

• For larger spills, pump as much freestandingliquid as possible into well marked containersfor future reclamation or disposal.

• Spread soda ash over spill area and wet down.Let stand for 2 hr., then flush with plenty ofwater.


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Reporting Requirements(Also see the appropriate section of the Material Safety Data Sheet for additional information.)

Determine if the release should be reported:• The three Hypo Products have not been as-

signed a CERCLA Reportable Quantity(RQ); however, releases may be reportable.

• Report any release of any amount if it couldcause harm to people or the environment, oras State or Local regulations require.

• It is best to report a spill if there is anyuncertainty.

When it has been decided that a release is re-portable, report immediately to the National Re-sponse Center [for CERCLA], in addition to ap-propriate State and Local agencies as requiredaccording to SARA.

National Response Center1-800-424-8802

Depending on specific conditions, the materialresulting from cleanup operations may be classi-fied as hazardous waste and therefore subject tospecific regulations.

Package, store, transport and dispose of allcleanup materials and any contaminated equip-

ment in accordance with all applicable federal,state and local health and environmental regula-tions. Shipments of waste material may be sub-ject to manifesting requirements per applicableregulations. Appropriate disposal will depend onthe nature of each waste material and should beperformed by competent and properly permittedcontractors. Ensure that all responsible Federal,State and Local agencies receive proper notifi-cation of spill and disposal methods.

Waste DisposalAny material that can not be used or chemicallyreprocessed should be disposed of in accor-dance with all Federal, State and Local regula-tions.

The three Hypo Products are not listed as sub-stance or source wastes under Federal RCRAHazardous Waste Classifications. However, ifdisposed of, Hypophosphorous Acid would beclassified as D002 hazardous waste due to itscorrosive characteristic.

Although all three products would be expected topass, they may require TCLP testing for hazard-ous constituents. It is important to be familiarwith State and Local waste disposal regulationsas they may be more stringent than the FederalRCRA requirements.

Registered Trademarks

OxyChem is a registered trademark of Occidental Chemical CorporationResponsible Care is a registered trademark of the Chemical Manufacturers Association, Inc.Teflon is a registered trademark of E. I. duPont de Nemours and Company

Documents

Hypo Products - Erowid · OxyChem ® emphasizes caution ... caustic soda, as a raw material. Sodium Hypophosphite ... Hypo Products Handbook Hypophosphorous Acid. …