Technical Note : Chemical Resistance for Geomembranes

Rowad geomembranes are made of high quality, virgin polyethylene which demonstrates excellent chemical resistance. Rowad polyethylene geomembranes are resistant to a great number and combinations of chemicals. It is this property of (HDPE) high density polyethylene geomembranes that makes it the lining material of choice.

In order to gauge the durability of a material in contact with a chemical mixture, testing is required in which the material is exposed to the chemical environment in question. Chemical resistance testing is a very large and complex topic because of two factors. First, the number of specific media is virtually endless and second, there are many criteria such as tensile strength, hardness, etc. that may be used to assess a material's resistance to degradation.

The chemical resistance of polyethylene has been investigated by many people over the past few decades. We are able to draw from that work when making statements about the chemical resistance of today's polyethylene geomembranes. In addition to that, many tests have been performed that specifically use geomembranes and certain chemical mixtures. Naturally, however, every mixture of chemicals cannot be tested for. As a result of these factors, Rowad published a chemical resistance chart, demonstrating general guidelines.

Polyethylene is, for practical purposes, considered impermeable. Be aware, however, that all materials are permeable to some extent. Permeability varies with concentration, temperature, pressure and type of permeant. The rates of permeation are usually so low, however, that they are insignificant. As a point of reference, polyethylene is commonly used for packaging of several types of materials. These include gaso line, motor oil, household cleaners (i.e. bleach), muratic acid, pesticides, insecticides, fungicides, and other highly concentrated chemicals. Also, you should be aware that there are some chemicals which may be absorbed by the material but only when present at very high concentrations. These include halogenated and/or aromatic hydrocarbons at greater than 50%; their absorption results in swelling and slight changes in physical properties such as increased tensile elongations. This includes many types of fuels and oils. Recognize that this action, however, does not affect the liner's ability to act as a barrier for the material it is containing.

Since polyethylene is a petroleum product, it can absorb other petroleum products. Like a sponge, the material becomes slightly thicker and more flexible but does not produce a hole or void. However, unlike a sponge, this absorption is not immediate. It takes a much longer time for a polyethylene liner to swell than it does for a sponge. The exact time it takes for swelling to occur depends on the particular constituents and concentrations of the contained media. However, a hole would not be produced. Also, this absorption is reversible and the material will essentially return to it's original state when the chemical is no longer in contact with the liner.

With regard to typical municipal landfills in the Africa, Australia & GCC legally allowable levels of chemicals have been demonstrated to have no adverse affect on polyethylene geomembrane performance. The very low levels of salts, metals and organic compounds do not damage polyethylene. A double-lined containment with a leachate (leak detection) removal system effectively prevents any significant, continuous exposure of the secondary membrane to these materials and for practical purposes makes the total liner system even more impermeable.

This information is provided for reference purposes only and is not intended as a warranty or guarantee. Rowad assumes no liability in connection with the use of this information. Please check with us for current. Standard minimum quality assurance procedures and specifications

Technical Note: Chemical Resistance Chart Produced by a world-leading supplier of high quality polyethylene geomembranes, Rowad's polyethylene geomembranes are resistant to a great number and combinations of chemicals. Note that the effect of chemicals on any material is influenced by a number of variable factors such as temperature, concentration, exposed area and duration. Many tests have been performed that use geomembranes and certain specific chemical mixtures. Naturally, however, every mixture of chemicals cannot be tested for, and various criteria may be used to judge performance. Reported performance ratings may not apply to all applications of a given material in the same chemical. Therefore, these ratings are offered as a guide only. This information is provided for reference purposes only and is not intended as a warranty or guarantee. Rowad assumes no liability in connection with the use of this information.

Resistance at:Medium Concentration 20C 60 C

(68 F) (140 F)A Acetic acid 100% S LAcetic acid 10% S SAcetic acid anhydride 100% S LAcetone 100% L LAdipic acid sat. sol. S SAllyl alcohol 96% S SAluminum chloride sat. sol. S SAluminum fluoride sat. sol. S SAluminum sulfate sat. sol. S SAlum sol. S SAmmonia, aqueous dil. sol. S SAmmonia, gaseous dry 100% S SAmmonia, liquid 100% S SAmmonium chloride sat. sol. S SAmmonium fluoride sol. S SAmmonium nitrate sat. sol. S SAmmonium sulfate sat. sol. S SAmmonium sulfide sol. S SAmyl acetate 100% S LAmyl alcohol 100% S LAniline 100% S LAntimony trichloride 90% S SArsenic acid sat. sol. S SAqua regia HCI-HNO3 U U

B Barium carbonate sat. sol. S SBarium chloride sat. sol. S SBarium hydroxide sat. sol. S SBarium sulfate sat. sol. S SBarium sulfide sol. S SBenzaldehyde 100% S LBenzene - L LBenzoic acid sat. sol. S SBeer - S SBorax (sodium tetraborate) sat. sol. S SBoric acid sat. sol. S SBromine, gaseous dry 100% U UBromine, liquid 100% U UButane, gaseous 100% S SI-Butanol 100% S SButyric acid 100% S L

C Calcium carbonate sat. sol. S SCalcium chlorate sat. sol. S SCalcium chloride sat. sol. S SCalcium nitrate sat. sol. S SCalcium sulfate sat. sol. S SCalcium sulfide dil. sol. L LCarbon dioxide, gaseous dry 100% S SCarbon disulfide 100% L UCarbon monoxide 100% S S

Chloracetic acid sol. S S

Resistance at:Medium Concentration 20C 60 C

(68 F) (140 F) Carbon tetrachloride 100% L UChlorine, aqueous solution Sat.sol. L U

Chlorine, gaseous dry 100% L UChloroform 100% U UChromic acid 20% S LChromic acid 50% S LCitric acid Sat.sol. S SCopper chloride sat. sol. S SCopper nitrate sat. sol. S SCopper sulfate sat. sol. S SCresylic acid sat. sol. L Cyclohexanol 100% S SCyclohexanone 100% S LD Decahydronaphthalene 100% S LDextrine sol. S SDiethyl ether 100% L Dioctylphthalate 100% S LDioxane 100% S SE Ethanediol 100% S SEthanol 40% S LEthyl acetate 100% S UEthylene trichloride 100% U UF Ferric chloride sat. sol. S SFerric nitrate sol. S SFerric sulfate sat. sol. S SFerrous chloride sat. sol. S SFerrous sulfate sat. sol. S SFluorine, gaseous 100% U UFluorosilicic acid 40% S SFormaldehyde 40% S SFormic acid 50% S SFormic acid 98-100% S SFurfuryl alcohol 100% S LG Gasoline - S LGlacial acetic acid 96% S LGlucose sat. sol. S SGlycerine 100% S SGlycol sol. S SH Heptane 100% S UHydrobromic acid 50% S SHydrobromic acid 100% S SHydrochloric acid 10% S SHydrochloric acid 35% S SHydrocyanic acid 10% S SHydrofluoric acid 4% S SHydrofluoric acid 60% S LHydrogen 100% S SHydrogen peroxide 30% S LHydrogen peroxide 90% S UHydrogen sulfide, gaseous 100% S SL Lactic acid 100% S SLead acetate sat. sol. S M Magnesium carbonate sat. sol. S SMagnesium chloride sat. sol. S SMagnesium hydroxide sat. sol. S SMagnesium nitrate sat. sol. S SMaleic acid sat. sol. S SMercuric chloride sat. sol. S S

Resistance at:Medium Concentration 20C 60 C

(68 F) (14O F)Mercuric cyanide sat. sol. S SMercuric nitrate sol. S SMercury 100% S SMethanol 100% S SMethylene chloride 100% L - Milk - S SMolasses - S SN Nickel chloride sat. sol. S SNickel nitrate sat. sol. S SNickel sulfate sat. sol. S SNicotinic acid dil. sol. S - Nitric acid 25% S SNitric acid 50% S UNitric acid 75% U UNitric acid 100% U U0 Oils and Grease - S LOleic acid 100% S LOrthophosphoric acid 50% S SOrthophosphoric acid 95% S LOxalic acid sat. sol. S SOxygen 100% S LOzone 100% L UP Petroleum (kerosene) - S LPhenol sol. S SPhosphorus tricWoride 100% S LPhotographic developer cust. conc. S SPicric acid sat. sol. S - Potassium bicarbonate sat. sol. S SPotassium bisulfide sol. S SPotassium bromate sat. sol. S SPotassium bromide sat. sol. S SPotassium carbonate sat. sol. S SPotassium cWorate sat. sol. S SPotassium chloride sat. sol. S SPotassium chromate sat. sol. S SPotassium cyanide sol. S SPotassium dichromate sat. sol. S SPotassium ferricyanide sat. sol. S SPotassium ferrocyanide sat. sol. S SPotassium fluoride sat. sol. S SPotassium hydroxide 10% S SPotassium hydroxide sol. S SPotassium hypochlorite sol. S LPotassium nitrate sat. sol. S SPotassium orthophosphate sat. sol. S SPotassium perchlorate sat. sol. S SPotassium permanganate 20% S SPotassium persulfate sat. sol. S SPotassium sulfate sat. sol. S SPotassium sulfite sol. S SPropionic acid 50% S SPropionic acid 100% S LPyridine 100% S LQ Quinol (Hydroquinone) sat. sol. S S5 Salicylic acid sat. sol. S S

Resistance at:Medium Conentration 20C 60 C

(68 F) (140 F)Silver acetate sat. sol. S SSilver cyanide sat. sol. S SSilver nitrate sat. sol. S SSodium benzoate sat. sol. S SSodium bicarbonate sat. sol. S SSodium biphosphate sat. sol. S SSodium bisulfite sol. S SSodium bromide sat. sol. S SSodium carbonate sat sol S SSodium chlorate sat. sol. S SSodium chloride sat. sol. S SSodium cyanide sat. sol. S SSodium ferricyanide sat. sol. S SSodium ferrocyanide sat. sol. S SSodium fluoride sat. sol. S SSodium hydroxide 40% S SSodium hydroxide sat. so I. S S

Sodium hypochlorite 15% active chlorine S S

Sodium nitrate sat. sol. S SSodium nitrite sat. sol. S SSodium orthophosphate sat. sol. S SSodium suI fate sat. sol. S SSodium sulfide sat. sol. S SSulfur dioxide, dry 100% S SSulfur trioxide 100% U USulfuric acid 10% S SSulfuric acid 50% S SSulfuric acid 98% S USulfuric acid fuming U USulfurous acid 30% S ST Tannic acid sol. S STartaric acid sol. S SThionyl chloride 100% L UToluene 100% L UTriethylamine sol. S LU Urea sol. S SUrine - S SW Water S SWine vinegar S SWines and liquors - S SX Xylenes 100% L UY Yeast sol. S SZ Zinc carbonate sat. sol. S SZinc chloride sat. sol. S SZinc (ll) cWoride sat. sol. S SZinc (IV) chloride sat. sol. S SZinc oxide sat. sol. S SZinc sulfate sat. sol. S S

Specific immersion testing should be undertaken to ascertain the suitability of chemicals not listed above with

ference to sre pecial requirements. NOTES: (S) Satisfactory: Liner material is resistant to the given reagent at the given concentration and temperature. No mechanical or chemical degradation is observed. (L) Limited Application Possible: Liner material may reflect some attack. Factors such as concentration. pressure and temperature directly affect liner performance against the given media. Application, however, is possible under less severe conditions. e.g. lower concentration, secondary containment. additional liner protections, etc. (U) Unsatisfactory: Liner material is not resistant to the given reagent at the given concentration and temperature. Mechanical and/or chemical degradation is observed. (-) Not tested sat. sol .= Saturated aqueous solution, prepared at 20 C (68 F)

sol. = aqueous solution with concentration above 10% but below saturation level dil. sol. = diluted aqueous solution with concentration below 10% cust. conc. = customary service concentration