# Summar**y of OECD 111 Tier 1 Testing:**  **Hy droly** **sis of**  **AL FOTERRA**  **® Surfactants**  **as a**  **Function of pH** 

# RESE **AR CH REPORT**  **Greg Trahan, Charles Hammond, Mark Bose, and Todd Houser**  **Research Report: R&D AN**  **L 10 -**  **004 01 -**  **10 July 13, 2010** 

**Sasol North A merica Incorporated**  **Research and Development Lake Charles, LA** 

**70669**

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## Test Substances The following materials were tested for hydroly tic stability

under OECD 111: OECD Guidelines for the Testing of Chemicals: Hydrolysis as a Function of pH . These alcohol propox y sulfates are manufactured to have an active component of 30 ± 5%. This translates to the product sold containing 25 - 35% alcohol propoxy sulfate. Additionally , there is up to 10% unsulfated starting mat erial, the propox y alcohol. The target value for unsulfated propox y alcohol is <5%. The balance of 55 - 65% is water. **Table I. Sasol Italy Substances Tested Under Tier I Guidelines of OECD 111 Trade Name**  **Comm on Name**  **Chemical Name CAS**  **Number Carbon** 

**chai n**  **Length PO** 

**Units (n)**  ALFOTERRA® 123 - 4S C12C13

branched propoxy sulfate, sodium salt Poly[oxy(methyl - 1,2 -

ethanediyl)], α - sulfo - ω hydroxy - , C12 - 13 -branched and linear alkyl ethers, sodium salts 958238 - 81 - 8 12 - 13 4 ALFOTERRA® 123 - 8S C12C13

branched propoxy sulfate, sodium salt Poly[oxy(methyl - 1,2 -

ethanediyl)], α - sulfo - ω hydroxy - , C12 - 13 -branched and linear alkyl ethers, sodium salts 958238 - 81 - 8 12 - 13 8 ALFOTERRA® 145 - 4S C14C15

branched propoxy sulfate, sodium salt Poly[oxy(methyl - 1,2 -

ethanediyl)], α - sulfo - ω hydroxy - , C14 - 15 -branched and linear alkyl ethers, sodium salts 958238 - 82 - 9 14 - 15 4 ALFOTERRA® 145 - 8S C14C15

branched propoxy sulfate, sodium salt Poly[oxy(methyl - 1,2 -

ethanediyl)], α - sulfo - ω hydroxy - , C14 - 15 -branched and linear alkyl ethers, sodium salts 958238 - 82 - 9 14 - 15 8 ALFOTERRA® L167 - 4S C16C17

branched and linear propoxy sulfate, sodium salt Poly[oxy(methyl - 1,2 -

ethanediyl)], α - sulfo - ω hydroxy - , C16 - 17 -branched and linear alkyl ethers, sodium salts 958238 - 83 - 0 16 - 17 4 C16C17 branched and linear propoxy sulfate, sodium salt Poly[oxy(methyl - 1,2 - ethanediyl)], α - sulfo - ω hydroxy - , C16 - 17 -branched and linear alkyl ethers, sodium salts 958238 - 83 - 0 16 - 17 7

### 3 **Figure 1. Structure of ALFOTERRA® Substances Studied**



## Buffer Solutions For Tier I testing, buffers were prepared on 6 - 22 - 10 according to “Annex 3” of OECD 111 . Each pH buffer prepared was tested with a calibrated pH meter, and the actual pH values for the buffers were found to be 4.0, 7.0, and 9.0 as intended. For details on the preparatio n of buffer solutions, refer to the procedure followed in Appendix I . 

## Test Conditions The tests performed in the Tier 1 hydrol ys is study were done in two separate batches of single replicate runs. ALFOTERRA® 123 - 4S and ALFOTERRA® 123 - 8S solutions were in cubated for five days from 6/23/10 to 6/28/10. ALFOTERRA® 145 - 4S, ALFOTERRA® 145 - 8S, ALFOTERRA® L167 - 4S, and ALFOTERRA® L167 - 7S solutions were incubated for five days from 7/1/10 to 7/6/10. Test solutions in 1 oz. vials were incubated in the dark, in a f orced air oven, which held an internal temperature of 50°C. 100 mLsamples were prepared for each test material at each pH required yielding buffered solutions with active concentrations between 0.25 and 0.35%. Two 1 oz vials were filled with approximate ly 30mL of each solution to make duplicate samples. One of the duplicates was incubated for five days and then anal yz ed, while the other duplicate was anal yz ed immediately to obtain a time “0” analy sis. Further details of the experimental method can be f ound in Appendix Iof this report. **Table II. Amount of Test Substance diluted in Buffer Solutions Test Material**  **Ma ss diluted to** 

**100mL with pH 4 buffer (g)**  **Ma ss diluted to** 

**100mL with pH 7 buffer (g)**  **Ma ss diluted to** 

**100mL with pH 9 buffer (g)**  ALFOTERRA® 1 23 - 4S 0.7434 0.7660 0.7332 ALFOTERRA® 123 - 8S 1.1844 1.1722 1.1633 ALFOTERRA® 145 - 4S 0.7342 0.7398 0.7483 

### C12 to C17 Carbon Chain Length 2 -4 carbon branchin g n = 4 – 8

### 4 ALFOTERRA® 145 - 8S 1.1196 1.1075 1.1019 ALFOTERRA® L167 - 4S 0.8947 0.9236 0.9051 ALFOTERRA® L167 - 7S 1.1305 1.1457 1.1224 

## Results ASTM D3049, Synthetic Anionic Ingredient by Cationic Titration, was the anal ys is used to quantify

the amount of material in each test sample . Sasol control charts show the repeatability

of this test to have a standard deviation of 0.16% when expressed as % active anionic surfactant. The amount of hydrol ys is that occurred was determined on a molar basis by comparing the meq/100mLof the time “0” sample to the that of the time “5 day” sample. The following equation gives the % reduction of active surfactant test material after incubation for 5 day s at 50°C. “meq/100mL of time 0” - “meq/100mL of time 5 days” % reduction = ----------------------------------------------------------------- x 100% “meq/100mL of time 0” 

### Table III. Reduction of Test Materials after **5 days at 50°C in pH 4 buffer Test Material**  **Time "0" A nalysis** 

**(meq active/100 mL) Time "5 Day" A**  **nalysis (meq active/100 mL)**  **% reduction** ALFOTERRA® 123 - 4S 0.4560 0.4373 4.10 ALFOTERRA® 123 - 8S 0.4670 0.4502 3.60 ALFOTERRA® 145 - 4S 0.4401 0.4248 3.4 8 ALFOTERRA® 145 - 8S 0.4578 0.4285 6.40 ALFOTERRA® L167 - 4S 0.4679 0.4437 5.17 ALFOTERRA® L167 - 7S 0.4682 0.4489 4.12 

### Table IV. Reduction of Test Materials after 5 days at 50°C in pH 7 buffer **Test Material Time "0" A**  **nalysis**

**(meq active/100 mL) Time**  **"5 Day" A nalysis**  **(meq active/100 mL) % reduction**  ALFOTERRA® 123 - 4S 0.4660 0.4581 1.70 ALFOTERRA® 123 - 8S 0.4550 0.4373 3.90 ALFOTERRA® 145 - 4S 0.4428 0.4358 1.58 ALFOTERRA® 145 - 8S 0.4505 0.4269 5.24 ALFOTERRA® L167 - 4S 0.4767 0.4758 0.19

### 5 ALFOTERRA® L 167 - 7S 0.4767 0.4599 3.52 

### Table V. Reduction of Test Materials after 5 days at 50°C in pH 9 buffer **Test Material Time "0" A**  **nalysis**

**(meq active/100 mL) Time "5 Day" A**  **nalysis (meq active/100 mL)**  **% reduction** ALFOTERRA® 123 - 4S 0.4239 0.4074 3.90 ALFOTERRA® 123 - 8S 0.4563 0.4428 3.00 ALFOTERRA® 145 - 4S 0.4529 0.4517 0.26 ALFOTERRA® 145 - 8S 0.4462 0.4395 1.50 ALFOTERRA® L167 - 4S 0.4703 0.4642 1.30 ALFOTERRA® L167 - 7S 0.4694 0.4673 0.45 

### According to the above data and OECD 111, the six materials test ed above are considered to be hydroly

tically stable since in all cases less than 10% hydroly sis was observed after 5 days of incubation at 50°C. No additional testing was performed under OECD 111 Tier 2 or Tier 3 guidelines.

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## Appendix I **Sasol Procedure Followed to determine Hydrolysis as a Function of pH:** 

**OECD 111 Tier I Testing** (Derived from OECD 111 Guidelines for the Testing of Chemicals:

Hydrolysis as a Function of pH) 1. Properly

clean glassware a. Wash volumetric flasks and other glassware in a laboratory glassware washer with deionized water prior to use. b. Rinse new 1 oz. vials for hydrol ys is study three times with 18 MOhm NANOpure water, and dry in a vacuum oven overnight at 100°C. 2. Calculate the amount of test material to be used in the hydrol ys is study . a. Solutions are to be made in 100mLvolumetric flasks. b. ASTM D3049, Synthetic Anionic Ingredient by Cationic Titrations, will be used to characterize samples. c. Id eall y, a 10mL aliquot of sample will be used to analyze via ASTM D3049, thus the amount of te st material to be added to each 100mL volumetric can be calculated b y “grams of sample = (0.045 x eq wt of active)/(% active)”. 3. Prepare pH 4.0, 7.0, and 9.0 buffers according to “Annex 3” of OECD 111: OECD Guidelines for the Testing of Chemicals: Hydrolys is as a Function of pH. a. Prepare pH 4.0 buffer b y combining 4.0mL of 0.1N NaOH and 500mL of 0.1M potassium biphthalate in a 1000mL volumetric flask. Dilute to volume with 18 MOhm NANOpure water and mix by inverting several times. b. Prepare pH 7.0 buffer b y c ombining 296.3mL of 0.1N NaOH and 500mL of 0.1M monopotassium phosphate in a 1000mL volumetric flask. Dilute to volume with 18 MOhm NANOpure water and mix by inverting several times. c. Prepare pH 9.0 buffer b y combining 213.0mL of 0.1N NaOH and 500mL of 0.1 M boric acid in 0.1M KCl in a 1000mLvolumetric flask. Dilute to volume with 18 MOhm NANOpure water and mix by inverting several times. 4. Test each pH buffer. a. Calibrate a pH meter with purchased pH 4, 7, and 9 standards. b. Check each buffer with the calibrat ed pH meter to ensure it is +/ - 0.1 units within the desired pH. c. Remake any pH buffers that do not fall with the +/ - 0.1 range of the target pH. 5. Sparge each pH buffer with argon for five minutes.

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## Note: The remaining steps should be repeated **for each individual material being tested.**  6. Purge and fill glassware with argon. a. Three 100mL volumetric flasks are required for each product tested. Purge and fill each with argon. b. Six 1 oz. vials are required for each product being tested. Purge and fill each with argon. 7. Charge each 100mL volumetric flask the appropriate amount of material being tested. a. Shake or mix the surfactant well before use. b. Weigh the appropriate amount of surfactant into three volumetric flasks using an anal ytical balance. c. Record the weight. 8. Dilute the three 100mL volumetric flasks. a. Dilute the three 100mL volumetric flasks to volume with pH 4.0, 7.0, and 9.0 buffers. b. Invert the flasks several times to thoroughl y mix. 9. Dispense the solutions to 1 oz. vials for testing. a. Fill two 1 oz. vials to the neck (~30 mL per vial) with the contents of each 100mLvolumetric flask. There will be six 1 oz. vials; a duplicate for each pH. b. Fill the headspace of the filled 1 oz. vials with argon. c. The remainder of the contents of the 100mLvolumetric flask can be retained or discarded. 10. Begin the hydrol ys is study . a. Place one of each pair of 1 oz vials in a equilibrated oven at 50°C. b. Submit the duplicate samples to the Analy tical Services Department immediately

for a time “0” anal ys is by ASTM D3049. i. If samples can not be analy zed immediately , place them in a refrigerator for storage. ii. Samples must be at room temperature before performing ASTM D3049 because sampling will be done by volume. 11. Allow the vials to remain in the oven for 5 day s. 12. After 5 day s, remove the vials from the oven and submit to the Analy tical services Department immediatel y for the final time “5 day” anal ys is by ASTM D3049. 13. Compare time “0” and time “5 day s” results to ascertain the amount of each sample that was hydrol yz ed.

### 8 a. If more than 10% of hydrolysis is observed after 5 days for any of the three pHs, proceed with Tier 2 testing.