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Appendix E Details on Candidate Surfactants Recommended for Further Evaluation
E-1 CANDIDATE SURFACTANTS Detailed information of candidates from promising surfactant categories is presented. Acetylenic diols These surfactants are often called Gemini surfactants because they contain two symmetric hydrophobic substructures. They are reported to provide good surface tension reduction and low foaming. ⢠Surfynol 465: Product of Air Products and Chemicals. Reported to give good wetting. The surfactant is formed by reacting ethylene oxide oligomers with 2,4,7,9-tetramethyl- 5-decyne-4,7-diol. On average there are 10 moles of ethylene oxide per mole of surfactant. The surface tension of a 1% solution with water is 25.8 dynes/cm. The surfactantâs HLB is 13. The cloud point of a 5% solution is 63°C. The 72 hr EC50 for Skeletonema costatum is 93 mg/L. The rat oral LD50 is 6,300 mg/kg. Alkoxylated branched alcohols In this class of surfactants the hydrophobe is a branched hydrocarbon and the lipophobe is a chain of ethylene oxide and/or propylene oxide repeat units. ⢠Tergitol TMN-6: Product of the Dow Chemical Company. A branched secondary alcohol ethoxylate. Reported to provide superior wetting. The critical micelle concentration in water at 25°C is 800 ppm. The surface tension of a 1% solution with water is 27 dynes/cm at 25°C. The surfactantâs HLB was reported to be 13.1. On average there are 8 moles of ethylene oxide per molecule. The hydrophobe is 2,6,8-trimethyl-4-nonanol. The Ross-Miles foam height for a 0.1% solution at 25°C was 150 mm initially and then 24 mm after five minutes. The cloud point of a 1% by weight aqueous solution is 36°C. The BOD was reported as 36% on day 20. The 96 hr LC50 for Pimephales promelas is 39 mg/L. The 48 hr LC50 for Daphnia is 81.2 mg/L. The rat oral LD50 is 3,260 mg/kg. ⢠Tergitol TMN-10: Product of the Dow Chemical Company. A branched secondary alcohol ethoxylate. The critical micelle concentration in water at 25°C is 1,313 ppm. The surface tension of a 1% solution with water is 30 dynes/cm at 25°C. The surfactantâs HLB was reported to be 14.4. On average there are 11 moles of ethylene oxide per molecule. The hydrophobe is 2,6,8-trimethyl-4-nonanol. The Ross-Miles foam height for a 0.1% solution at 25°C was 118 mm initially and then 28 mm at five minutes. The cloud point of a 1% by weight aqueous solution is 76°C. The BOD was reported as 33% on day 20. The 96 hr LC50 for Pimephales promelas is 103 mg/L. The 48 hr LC50 for Daphnia is 164.9 mg/L. The rat oral LD50 is 5.65 ml/kg. ⢠Lutensol XP 50: Product of the BASF Corporation. An ethoxylated branched C10 alcohol. The surface tension of a 0.1% solution with water is 26 dynes/cm at 23°C. The surfactantâs HLB is 10.0. On average there are 5 moles of ethylene oxide per mole of
APPENDIX E E-2 surfactant. The hydrophobe is a 2-propylheptyl group. Predicted to be readily biodegradable. ⢠Lutensol XP 100: Product of the BASF Corporation. An ethoxylated branched C10 alcohol. The surface tension of a 0.1% solution with water is 30 dynes/cm at 23°C. The surfactantâs HLB is 14.5. On average there are 10 moles of ethylene oxide per mole of surfactant. The hydrophobe is a 2-propylheptyl group. Estimated to have an LC50 for daphnia magna between 10 and 100 mg/L. Predicted to be readily biodegradable. Alkoxylated linear alcohols In this class of surfactants the hydrophobe is a linear hydrocarbon and the lipophobe is a chain of ethylene oxide and/or propylene oxide repeat units. At least five moles of ethoxylation is needed for aqueous applications. ⢠Triton DF-16: Product of the Dow Chemical Company. The MSDS reports the productâs main ingredient to be alkoxylated (ethoxylated and propoxylated) primary C8-C10 alcohols. It is reported to be readily biodegradable and a good low foaming wetting agent. The critical micelle concentration in water at 25°C is 530 ppm. The surface tension of a 1% solution with water is 30 dynes/cm at 25°C. The surfactantâs HLB is 11.6. The cloud point of a 1% aqueous solution is 36°C. Eighty-two percent of the product will biodegrade in 20 days. The male rat oral LD50 is 500 mg/kg. The 96 hr LC50 for Pimephales promelas is 13.3 mg/L. The female rat oral LD50 is 616 mg/kg. ⢠Bio-Soft N1-5: Product of Stephan Company. Comprised of ethoxylated C11 alcohol. Reported to give moderate foam production and promote excellent wetting. The surfactantâs HLB is 11.2. On average there are 5 moles of ethylene oxide per mole of surfactant. The cloud point of a 1% aqueous solution is 18°C. It is expected that 97% of this surfactant be primarily degraded in five to seven days and 84% ultimately degraded in 28 days. The 96 hr LC50 for Pimephales promelas ranges from 0.48 to 13 mg/L. The 48 hr LC50 for Daphnia magna ranges from 0.29 to 72 mg/L. The rat oral LD50 ranges from 2,000 to 3,340 mg/kg. ⢠Bio-Soft N1-7: Product of Stepan Company. Comprised of ethoxylated C11 alcohol. Reported to give moderate foam production and promote excellent wetting. The surfactantâs HLB is 12.9. On average there are 7 moles of ethylene oxide per mole of surfactant. The cloud point of a 1% aqueous solution is 58°C. It is expected that 97% of this surfactant be primarily degraded in five to seven days and 84% ultimately degraded in 28 days. The 96 hr LC50 for Pimephales promelas ranges from 0.48 to 13 mg/L. The 48 hr LC50 for Daphnia magna ranges from 0.29 to 72 mg/L. The rat oral LD50 ranges from 2,000 to 3,340 mg/kg. ⢠Merpol SE: Product of the Stepan Company. Reported to be a low foaming surfactant with excellent wetting properties. Use levels typically range from 0.01 to 0.1 wt%. The surface tension of a 0.01 wt% aqueous solution is 28 dynes/cm, a 0.1 wt% aqueous solution is 27 dynes/cm, and a 1.0 wt% aqueous solution is 27 dynes/cm. The solubility limit in water is 0.1 wt%. The surfactantâs HLB is calculated to be 10.5. The Ross-Miles foam height for a 0.1% solution at 40°C was 40 mm initially and 20 mm after ten minutes
APPENDIX E E-3 when conducted with soft water. The cloud point of a 1% aqueous solution is less than 3°C. ⢠Lutensol TDA 10: Product of the BASF Corporation. Also known as Iconol TDA-10. Comprised of ethoxylated tridecyl alcohol. Reported to have excellent rapid wetting properties and produce relatively low amounts of foam. The surface tension of a 0.1% aqueous solution is 31 dynes/cm at 25°C. The surfactantâs HLB is 14.0. On average there are 10 moles of ethylene oxide per mole of surfactant. ⢠Plurafac S-405LF: Product of the BASF Corporation. Comprised of alkoxylated C6 to C10 linear alcohols. At 25°C the surface tension of a 0.1 wt% aqueous solution is 32 dynes/cm, a 0.01 wt% aqueous solution is 31 dynes/cm and a 0.001 wt% aqueous solution is 73 dynes/cm. The Ross-Miles foam height for a 0.1 wt% solution is 20 mm initially and 0 mm after five minutes. The cloud point of a 1% aqueous solution is 28°C. Reported to be readily biodegradable. The rat oral LD50 is estimated to be between 2,380 and 2,745 mg/kg. Alkoxylated secondary alcohols In this class of surfactants the hydrophobe is a secondary hydrocarbon and the lipophobe is a chain of ethylene and/or propylene oxide repeat units. ⢠Tergitol 15-S-7: Product of the Dow Chemical Company. Secondary alcohol ethoxylate. Reported to provide superior wetting. The critical micelle concentration in water at 25°C is 38 ppm. The surface tension of a 1% solution with water is 30 dynes/cm at 25°C. The surfactantâs HLB was reported to be 12.1. On average there are 7 moles of ethylene oxide per mole of surfactant. The Ross-Miles foam height for a 0.1% solution at 25°C was 117 mm initially and then 28 mm after five minutes. The cloud point of a 1% by weight aqueous solution is 37°C. In 28 days the surfactant was more than 60% degraded. The 96 hr LC50 for this family of surfactants ranges from 3.4 to 4.9 mg/L. The 48 hr EC50 (immobilization) to Daphnia magna for this family of surfactants is 4.01 mg/L. The typical rat oral LD50 for this family of surfactants is estimated to be greater than 3,000 mg/kg. ⢠Tergitol 15-S-12: Product of the Dow Chemical Company. Secondary alcohol ethoxylate. The critical micelle concentration in water at 25°C is 104 ppm. The surface tension of a 1% solution with water is 33 dynes/cm at 25°C. The surfactantâs HLB is reported to be 14.5. On average there are 12 moles of ethylene oxide per molecule. The Ross-Miles foam height for a 0.1% solution at 25°C is 124 mm initially and 43 mm after five minutes. The cloud point of a 1% by weight aqueous solution is 89°C. Calculated molecular weight is 728 g/mol. Chemical oxygen demand 2.15 mg/mg. Theoretical oxygen demand 2.18 mg/mg. 96 hr LC50 for Pimephales promelas ranges from 6.9 to 10.9 mg/L. 48 hr LC50 for Daphnia magna is 8.7 mg/L. The rat oral LD50 is 2,909 mg/kg. Alkyl polyglucosides These surfactants are reported to have low toxicity and be highly biodegradable. Unfortunately they are also noted to produce stable foams. It is most likely that these will be used in conjunction with an anti-foam.
APPENDIX E E-4 ⢠Triton CG-110: Product of the Dow Chemical Company. The MSDS reports the productâs main ingredients are 60.0% D-glucopyranose, oligomeric, decyl octyl glycoside (CAS 68515-73-1), less than 2% decanol and less than 2% octanol. Reported to provide good wetting, be soluble in highly alkaline solutions and readily biodegradable. Also reported to produce moderately to highly stable foam. The critical micelle concentration in water at 25°C is 1748 ppm. The surface tension of a 1% solution with water is 27 dynes/cm at 25°C. The Ross-Miles foam height for a 0.1% solution at 25°C was 105 mm initially and then 100 mm after five minutes. The cloud point of a 1% by weight aqueous solution is greater than 100°C. The BOD values indicate 100% degradation on day 20. The 96 hr LC50 for Pimephales promelas is 190 mg/L. The 48 hr EC50 for Daphnia magna is 294 mg/L. Amine EO-PO copolymers Only a single candidate was found for this surfactant category. In general this category of surfactant is reported to provide good wetting and very low foaming. ⢠Tetronic 904: Product of the BASF Corporation. The surface tension of a 0.1% solution with water is 35 dynes/cm at 25°C. The surfactantâs HLB is between 12 and 18. The cloud point of a 1% aqueous solution is 74°C. EO-PO copolymers These surfactants are known to have low aquatic toxicity and be very low foaming. Unfortunately the presence of the propylene oxide chain inhibits biodegradation. Candidates from this category must be carefully evaluated to ensure they are not persistent in the environment. The surface tension of these surfactants is also higher than desirable. It is very likely they will need to be used in combination with a co-surfactant. ⢠Tergitol L-64: Product of the Dow Chemical Company. Reported to give good wetting, high thermal and chemical stability, and provide efficient foam control. The surface tension of a 1% solution with water is 44 dynes/cm at 25°C. The surfactantâs HLB was reported to be 15. The Ross-Miles foam height for a 0.1% solution at 25°C was 48 mm initially and then 18 mm after five minutes. The cloud point of a 1% by weight aqueous solution is 62°C. Biodegradation is greater than 60% after 28 days. LC50 for aquatic organisms is greater than 100 mg/L in the most sensitive species tested. ⢠Pluronic L44 NF: Product of the BASF Corporation. The surface tension of a 0.1% solution with water is 45 dynes/cm at 25°C. The surfactantâs HLB is between 12 and 18. The cloud point of a 1% aqueous solution is 65°C. Biodegradation is report to be between 0 and 10% at 28 days. The 96 hr LC50 for rainbow trout is estimated to be greater than 46.4 mg/L. The 48 hr EC50 for daphnia magna is estimated to be greater than 100 mg/L. Ethoxylated alkanolamides These surfactants have similar properties to ethoxylated alcohols. They are also more expensive than ethoxylated alcohols.
APPENDIX E E-5 ⢠Triton CF-32: Product of the Dow Chemical Company. The hydrophobe is an oligomer of propylene oxide. Reported to have exceptionally low foaming. The surface tension of a 1% solution with water is 37 dynes/cm at 25°C. The surfactantâs HLB was reported to be 11. The cloud point of a 1% by weight aqueous solution is 25°C. Only 34% is biodegraded after 20 days. The 96 hr LC50 for Pimephales promelas is 412 mg/L. The 96 hr LC50 for rainbow trout is 186 mg/L. The 48 hr EC50 for Daphnia is 660 mg/L. The male rat LD50 is 1,414 mg/kg. Other Surfactants Although three additional classes of surfactants were considered, specifically dialkyl dimethyl polysiloxanes, ethoxylated ether amines and ethoxylated fatty amines, no candidates were found with satisfactory properties. Antifoams These chemicals destabilize the liquid-air interface causing foam coalescence and breakage. Some of these products are dispersible but not soluble in water. Anti-foam dispersions may give a cloudy appearance to deicing and anti-icing fluids. Typically anti-foams are used in concentrations ranging from 0.02 to 0.05 wt%. ⢠Pluriol P1000: Product of the BASF Corporation. This anti-foam is a polypropylene glycol with an average molecular weight of 1000. Its solubility in water at 25°C is 0.22 wt%. The 96 hr LC50 for golden orfe is estimated to be greater than 100 mg/L. The rat oral LD50 is estimated to be greater than 2,000 mg/kg. ⢠Pluronic L101: Product of the BASF Corporation. This anti-foam is an EO-PO block copolymer. It has an HLB ranging from 1 to 7. It is not soluble in water. The 96 hr LC50 for golden orfe is estimated to be greater than 100 mg/L. ⢠Ridafoam NS 221: Product of the BASF Corporation. This anti-foam is non-silicone based. It is comprised of at least 80 wt% paraffin oils and petroleum distillates. The 96 hr LC50 for rainbow trout is reported to be greater than 1,000 mg/L. The 48 hr LC50 for daphnia magna is reported to be greater than 1,000 mg/L. The rat oral LD50 is reported to be greater than 5,000 mg/kg.
