Biodegradability and Aquatic Toxicity of ALFOTERRA® 

Surfactants

Research Report R&D ENV 06-001 01-06

Allen M. Nielsen

Geoff Russell

July 2006

Research & Development

Lake Charles, Louisiana
Interoffice Correspondence 

To Victoria Stolarski

From Allen M. Nielsen, Geoff Russell

Date July 12, 2006

Subject R&D ENV 06-001 01-06 Biodegradability and Aquatic Toxicity of 

ALFOTERRA® Surfactants

Key Words: ALFOTERRA surfactants, biodegradability, aquatic toxicity

This report documents the biodegradability and aquatic toxicity data that Sasol North America 

has generated on the ALFOTERRA® surfactants. These data will be used to support marketing 

efforts of the ALFOTERRA® product line into numerous applications in the US and overseas. 

The conclusions of these studies are as follows:

1. As the proportion of propylene oxide (PO) increases in an ALFOTERRA® surfactant, the 

rate and extent of primary and ultimate biodegradation decreases. It appears that four 

(4) moles of PO is the cut-off between acceptable (> 60% Theoretical CO2 production 

(ThCO2) or > 70% dissolved organic carbon (DOC) loss in 28 days) and unacceptable 

ultimate biodegradation in the OECD “ready” biodegradation tests.

2. None of the following had a significant change on the biodegradability of ALFOTERRA® 

surfactants: (1) Changes in the alkoxylation catalyst (NOVEL® II or KOH), (2) Changes 

in the hydrophobe carbon chain length from C11 to C15, nor (3) insertions of up to 2 

moles of ethylene oxide (EO) between the hydrophobe and the PO. 

3. Sulfation decreases biodegradation of these surfactants.

4. High levels of primary biodegradation occur with ALFOTERRA® surfactants but very 

little, if any, ultimate biodegradation occurs during laboratory simulations of secondary 

wastewater treatment.

5. Acute freshwater aquatic toxicities for ALFOTERRA® surfactants are similar to 

analogous commercially available alcohol ethoxylates (EO). Varying the hydrophobe 

chain length from C11 to C15 and the amount of PO from 2 to 8 moles do not 

significantly affect aquatic toxicities. The ISOFOL® based- ALFOTERRA® surfactants 

appear to be slightly less toxic.

Future Work: 

Future studies have been planned to address the following objectives:

1. To determine conclusively if sulfation of propoxylates impedes or decreases the 

biodegradation rate when compared to the analogous alkoxylates.

2. To determine if biodegradation rate is affected by capping the propoxylate with ethylene 

oxide before sulfation. 
R&D ENV 06-001 01-06

Page 3

3. To determine if sulfonation of alcohol propoxylates influences biodegradation differently 

than sulfation.

4. To extend the above biodegradation work to hydrophobe chain length greater than C15. 

5. To reconfirm the apparent poor ultimate biodegradation of ALFOTERRA® surfactants in 

simulated waste water treatment. 

Distribution: D.T. Plummer, M.F. Cox, K.B. Youngblood, K. L. Matheson, K.K. Kinsley, M. 

Bose, J. Hackett, T.G. Grumbles, D. Penney, P. Filler, K. Sharp, F. Monterisi, E. Dallara, G. 

Cassani, C. Schröder, R. Cohen, D. Schär, Library, Livelink
R&D ENV 06-001 01-06

Page 4

INTRODUCTION

ALFOTERRA® surfactants have been developed by Sasol North America for many potential 

applications. ALFOTERRA® surfactants are based on Sasol’s non-linear alcohols (C11-C18) 

such as ISALCHEM®, ISOFOL®, TDA, LIAL® or SAFOLTM which are propoxylated ( 2 to 8 

moles) and sulfated. They have been successfully used as the surfactant for clean-up of 

ground water contaminated with chlorinated hydrocarbons or heavy oils. Numerous industrial

and academic organizations have received samples of ALFOTERRA® surfactants for testing in 

a variety of additional applications. Most recently an opportunity has arisen for the possible use 

of ALFOTERRA® surfactants in Enhanced Oil Recovery (EOR). However, the use of

ALFOTERRA® surfactants in the US will require submission of a US EPA Pre-Manufacturer 

Notification (PMN) before commercial sales are allowed. 

Over the past several years some environmental fate and effects data has been generated by 

SNA which will be of value and interest as various applications of ALFOTERRA® surfactants 

are pursued. Specifically, multiple studies have addressed the effects of modifying the chemical 

structure of branched alcohol ethoxide or propoxide sulfates on the ultimate biodegradability 

including; (1) amount of propylene oxide (PO), (2) changes in the carbon chain length of the 

hydrophobe, (3) insertion of ethylene oxide (EO) between the hydrophobe and the PO, and (4) 

presence of a sulf(on)ate group. Additional studies addressed the influence of the alkoxylation 

catalyst on the biodegradability of non-sulfated EO/PO alkoxylates.

1,3

 The detailed plan 

outlining the systematic examination of ALFOTERRA® surfactants and the corresponding 

alkoxylates can be found in Research Project Plan AUS SBU 04-033.

2

The following report was written to document and summarize the available ALFOTERRA® 

surfactants’ environmental fate and effects data in a form that will be helpful in (1) evaluating 

the effects of selected changes to the chemical structure, (2) evaluating the effects of changing 

alkoxylation catalysts and (3) supporting marketing efforts of the ALFOTERRA® product line.

OBJECTIVES

 Determine the primary and ultimate biodegradability and aquatic toxicity profiles of 

ALFOTERRA® surfactants.

 Estimate the biological removal of ALFOTERRA® surfactants in laboratory simulations 

of secondary wastewater treatment.

 Evaluate the affect of hydrophobe chain length and propylene oxide (PO) quantity on 

biodegradability.

 Examine the idea that insertion of ethylene oxide (EO) improves the biodegradability of 

ALFOTERRA® surfactants.

 Uncover any influence of the alkoxylation catalysts (KOH or NOVEL II) on the 

biodegradability of the ALFOTERRA® surfactants and the corresponding alkoxides.

 Compare biodegradation data of an ALFOTERRA® surfactant and its alkoxylate 

analogue to determine if sulfation has an effect.

 Review freshwater aquatic toxicity data and correlate the results to structural changes in 

the ALFOTERRA® surfactant.

CONCLUSIONS

 As the proportion of propylene oxide (PO) increases in an ALFOTERRA® surfactant, 

the rate and extent of primary and ultimate biodegradation decrease. It appears that 

four (4) moles of PO is the cut off between acceptable ( > 60 % Theoretical CO2 
R&D ENV 06-001 01-06

Page 5

production ( ThCO2) or > 70% Dissolved Organic Carbon (DOC) loss in 28 days) and 

unacceptable ultimate biodegradation in the OECD “ready” biodegradation tests.

 None of the following had a significant effect on the biodegradation of ALFOTERRA® 

surfactants: (1) Changes in the alkoxylation catalyst (NOVEL® II or KOH), (2) changes 

in the hydrophobe carbon chain length from C11 to C15 nor (3) insertion of up to 2 

moles of EO prior to the propylene oxide. 

 Surprisingly, it appears that sulfation decreases biodegradation of these surfactants.

 High levels of primary biodegradation occur with ALFOTERRA® surfactants but very 

little, if any, ultimate biodegradation occurs during laboratory simulations of secondary 

wastewater treatment.

 Acute freshwater aquatic toxicities for ALFOTERRA® surfactants are similar to 

analogous commercially available alcohol ethoxylates (AE). Varying the hydrophobe 

chain length from C11 to C15 and the moles of PO from 2 to 8 moles do not significantly 

affect aquatic toxicities. The ISFOL® alcohol based - ALFOTERRA® surfactants 

appear to slightly less toxic.

EXPERIMENTAL MATERIALS AND METHODS

Test Materials

ALFOTERRA® 123-2S - Sample number for the propoxylate = V1110-170, MW of 

ISALCHEM®123Alcohol = 194 mg/mmole, MW of PO = 123.5 mg/mmole, Water = 327 ppm, 

Hydroxyl number = 189.0 mg KOH/g, PPG = 2.76 wt %, Free Alcohol = 10.19 wt %, NMR moles 

PO = 2.13, PO = 38.91 wt %, Average MW of propoxylate = 317.54 mg/mmole. Sample 

number for sulfate - V1086-30-2, Active = 26.4 wt %, Free oil = 0.86 wt %, Sodium Sulfate = 

0.26%. KOH was the propoxylation catalyst.

ALFOTERRA® 123-4S - Sample number for propoxylate = V1110-174, MW of ISALCHEM®123 

Alcohol – 194 mg/mmole, MW PO = 232.58 mg/mmole, Water = 245 ppm, Hydroxyl number = 

141.2 mg KOH/g, PPG = 4.78 wt %, Free alcohol = 1.49 wt %, NMR moles PO = 4.01, PO = 

54.52 wt %, Average MW of propoxylate = 426.58 mg/mmoles. Sample number for sulfate - 

V1086-30-3, Active = 29.8 wt %, Free oil = 0.76 wt %, Sodium Sulfate = 0.32 wt %. KOH was 

the propoxylation catalyst.

ALFOTERRA® 123-8S - Sample number for propoxylate = V1086-24-1, MW of 

ISALCHEM®123 Alcohol = 194 mg/mmole, MW PO = 425.14 mg/mmole, Water = 583 ppm, 

Hydroxyl number = 93.8mgKOH/g, PPG = 1.37%, Free alcohol = 0.27 wt %, NMR moles PO = 

7.33, PO = 68.6y wt %, Average MW of propoxylate = 425.14 mg/mole, Sample number for 

sulfate - V1086-25-1, Active = 28.8wt %, Free oil = 1.8 wt %, Sodium Sulfate = 0.28 wt %, 

sodium bicarbonate 0.13 wt %. KOH was the propoxylation catalyst.

ALFOTERRA® 145-2S – Sample number for propoxylate = V1110-166, MW of ISALCHEM® 

145 Alcohol = 219 mg/mmole, MW PO = 108.46 mg/mmole, Water = 481 ppm, Hydroxyl 

number = 183.8 mg KOH/g, PPG = 5.25 wt %, Free alcohol = 14.34 wt %, NMR moles PO = 

1.87, PO = 33.12 wt %, Average MW of propoxylate = 327.46 mg/mmole, Sample number for 

sulfate - V 1086-30-1, Active = 32.5 wt %, Free oil = 0.92 wt %, Sodium Sulfate = 0.30 wt %. 

KOH was the propoxylation catalyst. 
R&D ENV 06-001 01-06

Page 6

ALFOTERRA® 145-4S – Sample number for propoxylate = V1086-22-1, MW of ISALCHEM® 

145 Alcohol – 219 mg/mmole, MW PO = 207.6 mg/mmole, Water = 245 ppm, Hydroxyl number 

= 130.4 mg KOH/g, Free Alcohol = 1.07 wt %, PPG = .99 wt %, NMR moles PO = 3.58, PO = 

48.67 wt %, Average MW of propoxylate = 426.64 mg/mmole, Sample number for sulfate –

V1086-23-1, Active = 29.5 wt %, Free oil = 0.86 wt %, Sodium Sulfate = 0.17 wt%. KOH was 

the propoxylation catalyst.

ALFOTERRA® I 12-3S - Sample number for propoxylate = V1149-108-3, MW of ISOFOL® 12 

Alcohol – 186 mg/mmole, MW PO = 185.72 mg/mmole, Water = 581 ppm, Hydroxyl number = 

183.4 mg KOH/g, Free Alcohol = 4.54 wt %, PPG = 13.27 wt %, NMR moles PO = 3.2, PO = 

50.10 wt %, Average MW of propoxylate = 370.70, Samp mg/mmole, Sample number for 

sulfate – V1086-30-5, Active = 30.1 wt %, Free oil = 1.72 wt %, Sodium Sulfate = 0.1 wt %. %. 

KOH was the propoxylation catalyst.

ALFOTERRA® S 23-3S – Sample number for propoxylate = V1086-151-1, MW of SAFOLTM 23 

Alcohol = 193.9 mg/mmole, Hydroxyl number = 154.3 mg KOH/g, Free Alcohol = 0.6 wt %, PPG 

= 1.7 wt %, NMR moles PO = 2.93, Average MW of propoxylate = 363.6 mg/ mmoles, Sample 

number for sulfate – V1086-151-1a also V1191-164-15, Active = 30.0 wt %, Free oil = 1.3 wt %, 

Sodium Sulfate = 0.20 wt %, Average MW of sulfate = 466.6 mg/mmole. KOMe was the 

catalyst.

ALFOTERRA® S 23-5S – Sample number for propoxylate = V1086-151-2, MW of SAFOLTM 23 

Alcohol = 193.9 mg/mmole, Hydroxyl number = 122.5 mg KOH/g, Free Alcohol = 0.3 wt %, 

PPG = 4.3 wt %, NMR moles PO = 4.85, Average MW of propoxylate = 458.0 mg/mmole, 

Sample number for sulfate – V1086-151-2a also V1191-164-16, Active = 31.6 wt %, Free oil = 

2.3 wt %, Sodium Sulfate = 0.15 wt %, Average MW of sulfate = 561.0 mg/ mmoles. KOMe was 

the catalyst.

ALFOTERRA® S 23-8S – Sample number for propoxylate = V1086 -151-3, MW of SAFOLTM 23 

Alcohol = 193.9 mg/mmole, Hydroxyl number = 99.5 KOH/g, free Alcohol = 0.4 wt %, PPG = 4.5 

wt %, NMR moles PO = 7.59, Average MW of proproxylate = 564.0 mg/mmole, Sample number 

for sulfate – V10860151-3a and V1191-164-17, Active = 30.6 wt %, Free oil = 1.5 wt %, Sodium 

Sulfate = 0.13 wt %, Average MW of sulfate = 667.0 mg/mmole. KOMe was the catalyst.

ALFOTERRA® S 23-4S – Sample number for the sulfate = V1269-11-2, Active = 28.2 wt %, 

free oil = 0.4 wt %. Four mole propoxylate made from SAFOLTM 23 Alcohol using KOH as the 

catalyst.

ALFOTERRA® S 23-4S - Sample number for the sulfate = V1269-11-1, Active = 27.0 wt %, 

Free oil = 0.59 %. Four mole propoxylate made from SAFOLTM 23 Alcohol using the NOVEL® II 

catalyst.

ALFOTERRA® S 45-2S – Sample number for the sulfate = V1269-12-1, Active = 24.6 wt %, 

Free oil = 0.63 wt %. Two mole propoxylate made from SAFOLTM 45 Alcohol using KOH as the 

catalyst.

ALFOTERRA® S 45-2S – Sample number for the sulfate = V1269-12-2, Active = 24.6 wt %, 

Free oil = 0.63 wt %. Two mole propoxylate made from SAFOLTM 45 Alcohol using the 

NOVEL® II catalyst.
R&D ENV 06-001 01-06

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ALFOTERRA® S 23-4S – Sample number for the sulfate = V1269-8, Active = 29.2 wt %, Free 

oil = 0.35 wt %. Four mole propoxylate made from SAFOLTM 23 Alcohol using the NOVEL® II

catalyst.

ALFOTERRA® S 23-0.5 EO-4S – Sample number for the sulfate = V1269-30, Active = 29.5 wt 

%, Free oil = 0.25 wt %. O.5 mole ethoxylate + four moles propoxylate made from SAFOLTM 23 

Alcohol using the NOVEL® II catalyst.

ALFOTERRA® S 23-1.0 EO-4S - Sample number for the sulfate = V1269-31, Active = 29.0 wt 

%, Free oil = 0.33 wt %. One mole ethoxylate + four moles propoxylate made from SAFOLTM 

23 Alcohol using the NOVEL® II catalyst.

ALFOTERRA® S 23-2.0 EO-4S – Sample number for the sulfate = V1269-32, Active = 29.3 wt 

%, Free oil = 0.32 wt %. Two mole ethoxylate + four moles propoxylate made from SAFOLTM 23 

Alcohol using the NOVEL® II catalyst.

ALFOTERRA® S 23-2.0 EO-4S – Sample number for the sulfate = V1269-29, Active = 29.7 wt 

%, Free oil = 0.44 wt %. Two moles ethoxylate + four moles propoxylate made from SAFOLTM 

23 Alcohol using KOH as the catalyst.

C12 derived LAS – Sample number VO610-129-2, Active = 51.2 wt %, free oil = 1.25 wt %, 

Sodium Sulfate = 1.37 wt %. Aluminum Chloride alkylation of C12 olefin which is sulfonated and 

neutralized to a sodium salt.

JAPANESE ABS ALKANE-60 – Sample number 4998-191, Active = 51.36%, free oil = 2.5 wt 

%, Sodium Sulfate = 0.86 wt %. Conventional polypropylene based alkylate which is highly 

branched in the C12 alkyl chain which is then sulfonated and neutralized to give the sodium salt.

NALKYLENE® 550L derived LAS – Sample number – V1086-20-1, Active = 51.84 wt%, oil = 

1.26 wt %, Sodium Sulfate = 0.71 wt %. Average alkyl chain length = C11.69.

Biotest Systems

The OECD 301A: DOC die-away test was done as described in the OECD Guideline for 

Testing of Chemicals adopted July 17,1992. This is a 28-day aerobic biodegradation die-away 

test on 10-30 mg/L water soluble organic compounds (measured as dissolved organic carbon –

DOC) done in mineral salts medium inoculated with ≤ 30 mg/L total suspended solids (TSS) 

from natural sewage/soils or surface waters. Ultimate biodegradation is determined by 

measuring the DOC concentrations in the test flasks during the test. Primary biodegradation 

can also be measured by using some compound specific methodology such as methylene blue 

active substance (MBAS). The inoculum was derived from activated sludge obtained from the 

Anderson Mill Municipal Water Reclamation Facility (Austin, TX) and the supernatant from a 

suspension of 100 g soil in 500 mL of the mineral salts medium. The test was done at a starting 

concentration of 20 mg DOC/L for the test materials. Toxicity tests were done with 20 mg 

DOC/L test surfactant and 20 mg DOC/L sodium acetate. The sampling and determination of 

DOC concentrations were done as described in Research Report 6951-01-22-92. Concentrated 

sulfuric acid (1 drop) was used to preserve each 30 mL DOC sample. The determination of 

MBAS was done as described in Sasol North America Analytical Method V1.025-85. The 

MBAS samples were preserved by the addition of 1% by volume formaldehyde. The details of 

this test are found in SNA Research Notebook V1160 pages 97-135 and SNA Research 

Notebook V1086 pages 73-91. The test started on 9/21/99 and was finished on 11/30/99. 
R&D ENV 06-001 01-06

Page 8

The OECD 302A Inherent Biodegradability: Modified SCAS Test was done as described in 

the OECD Guideline for Testing Chemicals adopted May 12, 1981. The inoculum was derived 

from activated sludge obtained from the Anderson Mill Municipal Water Reclamation Facility

(Austin, TX). The test was done at a starting concentration of 20 mg DOC/L for the 

ALFOTERRA® surfactants and 20 mg active/L for the C12 LAS and ABS surfactants. The 

MBAS and DOC analyses were done as described in the OECD 301A test. The test was 

started on 10/19/99 and was completed on 11/24/99. The details are in SNA research notebook 

V1160 pages 119-147 and SNA research notebook V1086 pages 71-97.

The OECD 301F Manometric Respirometry Test was done as described in the OECD 

Guideline for Testing Chemicals adopted July 17, 1992 with the following minor modifications: 

(1) reduction in test material concentration from 100 mg to 20 mg to reduce possible toxicity to 

the inoculum, (2) reduction in the pH from 7.4 to 7.0 to improve the efficiency of CO2 removal, 

and (3) reporting of % ThCO2 ( theoretical maximum production of carbon dioxide) instead of % 

ThO2 ( theoretical maximum uptake of oxygen) to improve the accuracy of detecting ultimate 

biodegradation.

The biodegradation test was done on the ALFOTERRA® surfactants in quadruplicate using two

20 channel Coordinated Environmental Services (CES) Ltd (Cornwell, UK) aerobic electrolytic 

respirometer units following the OECD 301 F guideline with slight modifications (as noted 

above). The workings of the CES respirometer units and the collection of the CO2 data are 

described in Research Report R&D ENV 05-006 01-05. 

The inoculum for these tests was derived from the recycled sludge from the City of Lake 

Charles, Louisiana Domestic Waste Water Plant A. The sludge was aerated ~ 7 days prior to 

use. The inoculum in the test medium was adjusted to a final concentration of < 30 mg TSS/L. 

Sodium benzoate ( J.T. Baker – 99% purity was used as the positive reference material). 

Inoculum toxicity tests with 20 mg sodium benzoate and 20 mg of the ALFOTERRA® surfactant 

were also completed. The details of this test are given in SNA research notebooks V1240 page 

119 and V1255 page 69. 

 .

Definitive Acute Aquatic Toxicity Tests on Daphnia magna and Pimephales promelas

were done on several ALFOTERRA® surfactants and NALKYENE® 550L derived linear alkyl 

benzene sulfonate (LAS) by ENSR ( Ft. Collins, CO). The methods used for doing these tests 

were detailed in US EPA Method EPA/600/4-90/02/027F – 1993 and ASTM Method E729-96 –

1998. ENSR reports can be found in Appendix 1.

The OECD 301B CO2 Evolution ( Modified “Sturm” Test) Biodegradation Test was done as 

described in the OECD Guideline for Testing Chemicals adopted July 17, 1992 on several 

propoxylates derived from SAFOLTM and ISALCHEM® alcohols. These data were generated at 

contract laboratories in Europe at the request of Sasol Germany. These data are included in 

this report for comparative purposes only.

RESULTS AND DISCUSSION

Effect of PO on Primary and Ultimate Biodegradation of ISALCHEM® , ISOFOL® and 

SAFOLTM based - ALFOTERRA® Surfactants in OECD Screening Biodegradation Tests

The biodegradability of multiple ALFOTERRA® surfactants were tested using OECD 301A and 

301F methods. Results showing the effect of PO on biodegradation of ALFOTERRA® 

surfactants are detailed in Table 1. Figure 1 shows the biodegradation trends as a function of 

moles of PO. The data in figure 1 was developed by averaging the biodegradation values 
R&D ENV 06-001 01-06

Page 9

shown in Table 1 for the surfactants with the same number of moles of PO, irrespective of the 

hydrophobe. Complete documentation of these data is found in Tables 7, 8, 8A and Table 9.

From these data it is clear that as the proportion of PO increases in the ALFOTERRA® 

surfactant, the rate and extent of primary and ultimate biodegradation decreases.

Table 1.

Effect of PO on Primary and Ultimate Biodegradation in OECD Screening Tests

ALFOTERRA® Surfactant

OECD 301A OECD 301F

% MBAS Loss % DOC Loss % ThCO2

Pass 10-

day 

Window

28-Day

End 

Point

Pass 10-

day 

Window

28-Day

End 

Point

Pass 10-

day 

Window

28-Day

End 

Point

ISALCHEM 123-2S Yes 98.2 No 52.1 -- --

ISALCHEM 145-2S Yes 96.4 No 54.5 -- --

ISOFOL I12-3S Yes 96.3 No 46.4 -- --

ISOFOL 123-4S Yes 91.1 N0 28.7 -- --

ISOFOL 145-4S Yes 88.9 No 33.9 -- --

ISOFOL 123-8S No 46.1 No 10.9 -- --

SAFOLTM S45-2.Sa No 64.2

SAFOLTM S23-3S No 60.1

SAFOLTM S23-4Sa No 55.5

SAFOLTM S23-5S No 42.4

SAFOLTM S23-8S No 43.3

a. Average of data from surfactants made from NII or KOH alkoxylation catalysts found in table 9.

Figure 1.

Effect of PO on Primary and Ultimate Biodegradation of ISALCHEM® 123, 145, 

and SAFOLTM 23, 45 Alcohol Based ALFOTERRA® Surfactants in OECD 

Screening Tests

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9

Moles of PO

Bio

d

e

gra

d

atio

n

% MBAS Loss

% DOC Loss

% ThCO2

(a)Interpolated from 4 mole and 8 mole data

(a)
R&D ENV 06-001 01-06

Page 10

 

Primary biodegradation was measured by methylene blue active substance (MBAS) analytical 

method which detects any alteration to or biological cleavage of the original surfactant. Ultimate 

biodegradation, or complete breakdown of the molecule, was measured by the loss of total 

soluble organic carbon (DOC). It is also measured by the detection of CO2 produced by the 

biological activity (%ThCO2). While the high MBAS values suggests the rate and extent of 

primary biodegradation of ISALCHEM® and ISOFOL® based- ALFOTERRA® surfactants with ≤

4 moles PO is extensive, the ultimate biodegradation was not acceptable (< 70% DOC removal 

in 28 days in the OECD 301 D test). On the other hand, the SAFOLTM based- ALFOTERRA® 

surfactants with < 4 moles PO did show acceptable ultimate biodegradation (> 60% ThCO2 in 

28 days in the OECD 301 F test). Table 8A contains data that confirms that ALFOTERRA® 

surfactants are not toxic to the inoculum.

It appears that if an ALFOTERRA® surfactant has ≥ 4 moles PO, it will not undergo “ready” 

biodegradability in the OECD Biodegradation screening tests. It also is apparent that changes 

in carbon chain length of the alcohol hydrophobe from C11 to C15 have very little, if any, effect 

on the rate or extent of biodegradation of ALFOTERRA® surfactants. These data are 

summarized in Table 1.

The use of KOH or NOVEL® II as the alkoxylation catalyst appears to have an insignificant 

effect on the biodegradation of the resulting ALFOTERRA® surfactant. As shown in table 2, the 

degradation end-points for surfactants made from either KOH or NOVEL II catalyst are not 

significantly different.

Table 2.

Effect of PO Catalysta on Ultimate Biodegradation of SAFOLTM Based ALFOTERRA® 

Surfactants

ALFOTERRA® Surfactant 

(SAFOLTM)

OECD 301F

Pass 10-Day Window 28-Day End Point

Mean ± Std. Dev.

S23-4 NII S No 46.5 NDb

S23-4 NII S No 69.9 ± 10.3

S23-4 KOH S No 50.0 ± 2.9

S23-2 EO-4 NII S No 59.2 ± 6.1

S23-2 EO-4 KOH S No 56.6 ± 8.8

S45-2 NII S No 62.3 ± 0.5

S45-2 KOH S No 66.1 ± 1.8

aNII = NOVEL® II catalyst, KOH = potassium hydroxide

bND = Not determined, only one value

Insertion of up to 2 moles of EO before the 4 moles of PO in SAFOLTM based- ALFOTERRA® 

surfactants had very little, if any, effect on the rate or extent of ultimate biodegradation in the 

OECD 301 F screening test as shown in Table 3 and documented in Table 9. All values are 

within the standard deviation of each other.
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Table 3.

Effect of EO Insertion on Ultimate Biodegradation of SAFOLTM Based ALFOTERRA® 

Surfactants in OECD Screening Test

ALFOTERRA® Surfactant 

(SAFOLTM)

OECD 301F

Pass 10-Day Window 28-Day End Point

Mean ± Std. Dev.

S23-4 S No 55.5 ± 12.6a

S23-0.5 EO-4S No 59.7 ± 5.6

S23-1.0 EO-4S No 60.8 ± 8.8

S23-2.0 EO-4S No 57.9 ± 7.5

a. Average of values from Table 9.

Sulfation apparently does have a significant effect on the ultimate biodegradation of 

ALFOTERRA® surfactants. That is, the addition of the sulfate group significantly decreases the 

biodegradation that was observed for the parent alkoxylate. This effect was demonstrated by 

the data in Table 4 and by the documentation in Table 9 and 10. Although the sulfate and the 

alkoxylates were tested at different times and with slightly different methods, the significant 

difference in the %ThCO2 after 28 days leads to the conclusion that ultimate biodegradation 

was impeded by the sulfate group. That is, the sulfated 2-mole EO / 4-mole PO SAFOL based 

surfactant showed only 58% ThCO2 at the end of the 28-day test while the parent alkoxylate 

showed 96%.

Table 4.

Apparent Effect of Sulfation on Ultimate Biodegradation in OECD Screening Tests

ALFOTERRA® 

(SAFOLTM)

OECD 301F OECD 301B

Pass 10-Day 

Window

28-Day End 

Point %ThCO2

Pass 10-Day 

Window

28-Day End 

Point %ThCO2

S23-2EO-4PO-S No 57.9

Alkoxylate 

(SAFOLTM)

S23-2EO-4PO Yes 95.7

S23-5EO-4PO Yes 96.1

S23-5EO-5PO Yes 87.7

S23-5EO-6PO Yes 86.1

This observation does not seem logical since sulfatase enzymes are widely distributed in 

nature. It would be expected that the sulfate group should be easily and rapidly removed in 

biodegradation tests. (The high level of primary biodegradation noted above in Figure/Table 1

is consistent with this idea). However, MBAS reduced detection is not a specific indicator of 

sulfate removal but a measure of any change in the molecule structure. The decrease in 

biodegradation by the addition of the sulfate group has been reported in earlier work. A 1979 

paper by Pitter showed that sulfation of nonylphenol ethoxylates deteriorates the biodegradation 

of these substances when compared to their alkoxylates.

Biological Removal of ISALCHEM® and ISOFOL® based- ALFOTERRA® Surfactants in 

Simulation of Secondary Wastewater Treatment (SCAS test)

ALFOTERRA® surfactants were evaluated by the SCAS test method which simulated the 

biological breakdown expected during processing at a water treatment facility. It is clear from 

the summary of SCAS data in Table 5 and more complete documentation in Tables 11,11A that 
R&D ENV 06-001 01-06

Page 12

all ALFOTERRA® surfactants will undergo some primary biodegradation when in contact with 

the biomass in water treatment sludge. However, only those ALFOTERRA® surfactants with ≤4 

moles of PO showed levels greater than 80%. This high level of primary biodegradation was 

probably due to the sulfatase enzymes activity present in the biomass. 

Only those ALFOTERRA® surfactants with ≤ 2 moles PO showed any (17-27%) ultimate 

biodegradation as measured by loss of DOC. The ALFOTERRA® surfactants with more than 2 

moles of PO did not undergo any measurable ultimate biodegradation at all. This result was 

similar to that observed for the propylene-based highly-branched ABS which was included as a 

negative control. In contrast, C12 LAS, added as a positive control, showed nearly complete 

ultimate biodegradation (97.5% DOC loss) in the SCAS test as expected. 

The lack of ultimate biodegradation of the ALFOTERRA® surfactants was confirmed by the loss 

of biomass (measured by loss of TSS) in the SCAS units fed ALFOTERRA® surfactants as 

shown in Figure 2. Note that the loss of biomass (TSS) in the units fed ALFOTERRA® 

surfactants was even more rapid than that observed in the blank unit which was fed only the 

background feed suggesting that the ALFOTERRA® surfactants were not a sufficient foodsource to support the biomass colony. On the other hand, SCAS units fed the rapidly 

biodegraded C12 LAS showed an increase in biomass, as measured by TSS, over the same 

time period.

Table 5.

Biological Removal of ISALCHEM®-based ALFOTERRA® Surfactants in Laboratory

Simulation of Secondary Wastewater Treatment (SCAS)

ALFOTERRA® 

(ISALCHEM®)

%MBAS Loss %DOC Loss

123-2S 99.8 17.2

145-2S 97.0 26.9

I12-3S (ISOFO®L) 88.4 0.0

145-4S 82.8 0.0

123-8S 51.9 0.0

Alkylbenzene Sulfonates

C12 LAS 99.8 97.5

ABS 37.7 0.0
R&D ENV 06-001 01-06

Page 13

Figure 2. 

Loss of TSS in SCAS Units Fed ISALCHEM® or ISOFOL® Based ALFOTERRA® 

Surfactants

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

2750

0 1 2 3 4 5 6 7 8 9 10 11 12

Days

T

S

S (mg/L)

2 Moles PO

3 Moles PO

4 Moles PO

8 Moles PO

Blank

From the SCAS tests, it can be concluded that the ISALCHEM®, and ISOFOL® basedALFOTERRA® surfactants with ≤4 moles PO undergo high levels of primary biodegradation. 

However, the ALFOTERRA® surfactants, regardless of PO addition levels, undergo very little 

or, in some cases, no ultimate biodegradation during simulation of secondary waste water 

treatment.

Acute Freshwater Aquatic Toxicity of ISALCHEM® and ISOFOL® based ALFOTERRA® 

Surfactants

The results of acute aquatic toxicity tests for the ALFOTERRA® surfactants to invertebrates –

water fleas (Daphnia magna) and fresh water fish- fathead minnows (Pimephales promelas)

are summarized in Table 6. The ENSR reports are found in Appendix one. 

Table 6.

Acute Aquatic Toxicity of ALFOTERRA® Surfactants

ALFOTERRA® Surfactant Daphnia magna

48-hr. LC50

mg/L (95% CL)

Pimephales promelas

96-hr. LC50

mg/L (95% CL)

123-2S 2.06 (1.76-2.29) 4.65 (4.27-5.08)

123-8S 2.65 (2.12-3.20) 1.68 (1.56-1.81)

I12-3S 8.88 (6.51-9.85) 10.99 (10.23-11.80)

145-2S 2.19 (1.86-2.49) 2.31 (2.14-2.48)

145-4S 2.34 (2.01-2.73) 1.62 (1.51-1.74)

Comparison Surfactant

N-550L LAS 11.93 (10.02-14.48) 3.89 (3.55-4.21)
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Page 14

Tests were done at ENSR, Ft. Collins, Colorado. Test numbers were 8503-111-006-15, 16, 17, 

18, 19, 20 and 8503-106-006-001, 002, 003, 004, 005, 006, 007, 008. These results were 

reported in ENSR letters dated March 18, 1999, and September 24, 1999.

The acute freshwater aquatic toxicity for the ALFOTERRA® surfactants are similar to those for 

analogous commercially available alcohol ethoxylates suggesting that the toxicity is acceptable. 

Carbon chain length (C11-C15) of the hydrophobe and moles of PO (2 to 8 moles) do not 

appear to be significant factors. The ISOFOL® based- ALFOTERRA® surfactant may be 

slightly less toxic than the ISALCHEM® based surfactants.

Future Work

There is a common perception that sulfated materials should be easily biodegraded by the 

plethora of sulfatase enzymes occurring naturally in soil and water. However, the above work 

suggests that the rate and extent of biodegradation of the sulfated ALFOTERRA® surfactants 

were significantly less than that of their unsulfated counterparts. This theory has also been 

proposed in earlier work by Pitter and Fuka.3It is proposed that the conformational 

arrangement of the propoxylate sulfate provides a clue to the poor biodegradation observed. 

Figure 3 shows a 3-D space filling model of a linear ethoxylate sulfate, a branched ethoxylate 

sulfate, and a branched propoxylate sulfate. Note the difference in the packing around the 

sulfate head. It is believed that the bulkiness of the propoxylate group surrounds the sulfate and 

thus, may impede the attack by the sulfatase enzymes. This impact in fact is greater than the 

effect observed for sulfated ethoxylates. 

Alcohol Ether Sulfate

Types of Surfactants

C14 EO3-sulfate

(linear alcohol)

C14 EO3-sulfate

(C4 branch at the #2 carbon)

C14 PO3-sulfate

(C4 branch at the #2 carbon;

Propylene oxide instead of 

ethylene oxide)

Figure 3.

Space filling model for various alkoxylate sulfate.

Continuing with this hypothesis, these models also explain why neither the choice of 

alkoxylation catalyst nor the insertion of EO showed an improvement to the biodegradation of 

the sulfated propoxylates. Neither condition changed the crowding around the sulfate group.
R&D ENV 06-001 01-06

Page 15

In a 1986 journal article, Gerike discusses biodegradability of propoxylates.4 From his work it 

can be inferred that the biodegradability of alcohol propoxylates will improve with the addition of 

ethylene oxide after the PO; if this holds true then a similar affect should be seen with the 

sulfated version. Thus, comparing the propoxylate sulfate to a propoxylate sulfate with EO 

inserted between the two functional groups will be one of the objectives of the future work

To continue to derive the structure/property relationship of alkoxylate sulfates the following

objectives will be addressed in future work:

1. To determine conclusively if sulfation of propoxylates impedes or decreases the 

biodegradation rate when compared to the analogous alkoxylates.

2. To determine if biodegradation rate is affected by capping the propoxylate with ethylene 

oxide before sulfation. 

3. To determine if sulfonation of alcohol propoxylates influences biodegradation differently 

than sulfation.

4. To extend the above biodegradation work to hydrophobe chain length greater than C15. 

5. To reconfirm the apparent poor ultimate biodegradation of ALFOTERRA® surfactants in 

simulated waste water treatment. 

ACKNOWLEDGEMENTS

The authors acknowledge Mark Bose for doing the DOC analysis; Rachel Washburn for 

execution of the hand-shake MBAS analysis and Rebekah Cohen for excellent help with the 

data handling and execution of the electrolytic respirometer (OECD 301F) tests. 

REFERENCES

1. Rowe, L., Steiniger, D., Matheson, L., and Russell, G. 2004. Analytical and Performance 

Results for Commercially-Produced Biodac 2-32 and Lab-Produced NOVEL® II Biodac 

2-32 Alkoxylates. SNA Research Report AUS ANL 03-004 01-03.

2. Russell, G. 2005. Gate B Document: Phase II ALFOTERRA® Surfactants: Improving the 

Biodegradability of ALFOTERRA® Surfactants, Alkyl Propoxylate Sulfates.

3. Schoenkaes, U., Grothe, R., and Mayer U., 2004. Low-foaming Surfactants Based on 

SAFOLTM 23 Alcohols, Project Marl TE 97/005 (TDO 153): Development of 

Biodegradable Alcohol EO-PO Derivatives. Technical Report FEA 5, April 15, 2004.

4. Pitter, P., and Fuka, T. Biodegradation of Non-sulfated and Sulfated Nonylphenol 

Ethoxylate Surfactants. Environment Protection Engineering (1979), 5 (1), 47-56

5. Gerike, P., Jasiak, W., 1986. How Completely are Surfactants Biodegraded?. Tenside 

Detergents, 23 (1986) 6; pg 300-304.
R&D ENV 06-001 01-06

Page 16

Table 7.

Biodegradation of ALFOTERRA® Surfactants in the OECD 301A Test

Surfactant % MBAS Loss

1 6 9 10 13 15 17 22 28

ALFOTERRA® 123-2S

Std. Dev.

5.1

± 0.5

95.8

± 0.2

97.4

± 0.2

97.6

± 0.3

97.2

± 1.5

98.4

± 0.1

97.5

± 0.2

98.3

± 0.1

98.2

± 0.2

ALFOTERRA® 123-4S

Std. Dev.

10.1

± 5.5

87.6

± 2.2

86.9

± 0.4

86.8

± 0.3

88.6

± 0.2

91.5

± 0.6

89.0

± 0.6

--

--

91.1

± 0.6

ALFOTERRA® 123-8S

Std. Dev.

5.3

± 1.7

35.8

± 4.2

46.0

± 3.2

39.9

± 5.6

45.5

± 0.9

51.6

± 2.5

45.3

± 1.3

--

--

46.1

± 0.3

ALFOTERRA® 145-2S

Std. Dev.

8.3

± 1.8

97.2

± 0.2

96.7

± 0.1

97.6

± 0.1

97.8

± 0.3

98.6

± 0.2

--

--

--

--

96.4

± 0.1

ALFOTERRA® 145-4S

Std. Dev.

4.7

± 1.41

86.4

± 0.7

87.9

± 0.2

88.9

± 1.9

88.8

± 0.1

88.8

± 2.5

88.1

± 2.5

--

--

88.9

± 2.3

ALFOTERRA® I12-3S

Std. Dev.

4.7

± 1.4

86.3

± 0.7

87.9

± 0.2

88.9

± 1.9

88.8

± 0.1

89.1

± 2.8

95.2

± 0.3

--

--

96.3

± 0.4

C12 LAS

Std. Dev.

0

± 0

99.8

± 0.3

98.9

± 0.4

98.7

± 0.6

99.7

± 0.1

100

± 0.1

98.4

± 0.9

99.0

± 0.2

99.0

± 0.3
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Page 17

Table 8.

Ultimate Biodegradation of ALFOTERRA® Surfactants in OECD 301A Test

Surfactant % DOC Loss

1 3 6 9 10 13 15 17 22 28

ALFOTERRA® 123-2S

Std. Dev.

8.4

± 11.9

20.8

± 1.6

29.2

± 0.1

38.3

± 1.0

39.6

± 3.5

43.0

± 0.6

47.3

± 2.8

53.7

± 2.1

56.7

± 1.34

52.1

± 1.41

ALFOTERRA® 123-4S

Std. Dev.

3.9

± 1.3

1.4

± 1.6

8.8

± 2.8

16.1

± 0.4

17.4

± 1.1

17.1

± 0.2

21.5

± 2.1

28.0

± 0.6

29.9

± 3.3

28.7

± 2.5

ALFOTERRA® 123-8S

Std. Dev.

0

± 0

0

± 0

1.3

± 1.8

0

± 0

10.9

± 4.2

5.7

± 1.3

4.7

± 0.8

14.0

± 0.8

15.1

± 2.3

10.9

± 1.6

ALFOTERRA® 145-2S

Std. Dev.

2.4

± 0.2

21.6

± 0.5

28.8

± 0.5

37.8

± 2.2

42.8

± 0.2

43.3

± 0.8

45.2

± 2.9

51.5

± 0.8

54.6

± 3.1

54.5

± 3.5

ALFOTERRA® 145-4S

Std. Dev.

2.7

± 0.9

2.9

± 1.3

13.3

± 3.5

18.2

± 0.8

24.8

± 0.1

26.3

± 2.1

28.1

± 4.2

34.7

± 0.6

36.2

± 1.2

33.9

± 1.3

ALFOTERRA® I12-3S

Std. Dev.

13.8

± 7.7

1.7

± 2.4

5.8

± 0.5

13.8

± 2.2

24.4

± 1.2

25.5

± 2.5

35.4

± 2.7

40.0

± 0.1

45.7

± 2.5

46.4

± 4.9

Acetate

Std. Dev.

88.9

± 9.5

97.4

± 0.8

96.5

± 0.5

98.5

± 1.5

96.5

± 0.3

99.2

± 1.3

97.6

± 0.9

98.3

± 2.5

96.5

± 1.1

100

± 0

C12 LAS

Std. Dev.

13.4

± 3.1

20.9

± 7.1

79.0

± 5.2

83.3

± 3.5

86.8

± 3.6

87.1

± 0.4

92.1

± 0.7

92.9

± 1.4

89.7

± 0.4

95.5

± 1.8
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Page 18

Table 8A.

Non-Toxicity of ALFOTERRA® Surfactants

(ALFOTERRA® + Sodium Acetate)

ALFOTERRA® Surfactant

(+ NaAcetate)

28-Day End Point

% DOC Loss

Predicted Measured

123-2S 75.4 79.3

123-4S 62.6 66.3

123-8S 55.2 61.7

145-2S 73.3 80.3

145-4S 64.4 69.5

I12-3S 71.3 73.5
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Page 19

Table 9.

Biological Mineralization of ALFOTERRA® Surfactants in the OECD 301F Eletrolytic Respirometer Biodegradation Test

ALFOTERRA® 

Surfactants

%ThCO2

1 2 3 4 6 8 10 12 14 16 18 20 22 24 26 28

SAFOLTM 45-2 (NII) S

± Std. Dev.

0.1

0.4

4.8

0.3

16.3

0.2

23.8

0.2

36.8

0.4

47.4

0.3

52.0

0.2

54.5

0.3

56.1

0.5

56.4

0.1

57.7

0.2

58.3

0.9

59.2

1.0

60.0

0.8

61.6

0.6

62.3

0.5

SAFOLTM 45-2 (KOH) S

± Std. Dev.

0

0

5.3

0.7

16.5

1.2

24.5

1.2

37.7

0.6

47.8

0.4

52.5

0.4

55.5

0.6

57.3

0.7

58.8

0.3

60.5

0.3

61.2

0.6

62.5

0.8

63.8

1.3

65.3

1.6

66.1

1.8

SAFOLTM 23-3 (KOMe) S

± Std. Dev.

0

0

3.4

0.1

11.3

0.3

19.6

0.5

33.4

0.2

41.1

2.3

45.1

2.6

49.2

2.0

51.2

1.7

53.1

1.5

54.7

0.8

56.0

1.1

56.8

1.0

58.0

1.0

59.6

1.0

60.1

0.8

SAFOLTM 23-4 (NII) S 0 2.2 8.7 14.5 24.4 29.7 33.3 35.6 36.4 37.7 41.6 43.9 43.7 45.0 46.2 46.5

SAFOLTM 23-4 (KOH) S

± Std. Dev.

0.1

0.4

2.3

0.7

8.3

0.4

14.8

1.3

26.9

2.6

33.8

0.1

37.9

1.3

41.4

2.0

43.2

2.7

43.8

3.5

45.6

3.1

46.6

2.9

46.9

3.2

47.7

3.4

49.6

2.9

50.0

2.9

SAFOLTM 23-5 (KOMe) S 0.7 1.0 2.8 4.4 12.1 19.4 23.9 28.3 30.9 31.7 34.3 34.8 36.3 38.6 41.7 42.4

SAFOLTM 23-8 (KOMe) S

± Std. Dev.

0

0

1.3

0.7

4.1

0.3

8.3

0.1

20.8

2.0

26.8

2.2

30.3

2.4

33.7

2.6

35.6

2.4

36.6

2.7

38.2

2.4

39.2

2.5

40.3

3.0

41.3

3.1

42.9

3.2

43.3

3.3

SAFOLTM 23-4 (NII) S

± Std. Dev.

0.2

0.8

2.3

0.5

8.6

0.3

15.5

1.1

31.6

4.2

43.3

4.5

49.7

5.9

52.6

6.4

55.0

5.6

56.8

5.1

57.6

3.9

60.8

3.7

61.4

3.5

64.3

8.2

66.6

8.7

69.9

10.3

SAFOLTM 23-0.5EO4

(NII) S

± Std. Dev.

0.6

1.2

2.9

1.4

9.3

2.3

15.5

2.6

27.7

4.2

36.2

5.0

41.4

6.4

45.4

8.2

49.0

7.7

50.8

6.9

52.0

6.2

54.6

5.6

53.2

7.0

53.3

7.2

56.4

5.9

59.7

5.6

SAFOLTM 23-1EO-4(NII)S

± Std. Dev.

0.2

2.4

1.9

3.1

7.0

1.8

13.9

2.3

28.7

2.4

39.6

2.1

45.8

3.1

51.6

5.4

54.5

6.8

55.5

7.8

56.0

7.6

58.2

9.7

54.9

5.0

53.5

4.1

57.4

5.9

60.8

8.8

SAFOLTM 23-2EO-4(NII)S

± Std. Dev.

0.1

1.2

1.2

0.6

7.6

0.6

14.0

0.9

27.0

1.7

36.2

1.2

42.9

1.3

46.3

0.6

49.5

3.0

53.5

8.1

54.1

7.9

54.3

6.9

53.5

2.5

53.5

1.3

56.9

3.8

59.2

6.1
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Page 20

ALFOTERRA® 

Surfactants

%ThCO2

1 2 3 4 6 8 10 12 14 16 18 20 22 24 26 28

SAFOLTM 23-2EO-4 

(KOH)S

± Std. Dev.

0.4

1.0

1.5

2.2

7.3

0.4

10.9

1.7

23.6

0.9

33.3

2.1

40.1

1.9

44.9

3.2

46.9

3.9

48.7

4.2

50.2

5.6

51.2

6.2

51.0

8.3

49.3

9.0

52.8

7.6

56.6

8.8

Sodium Benzoate

± Std. Dev.

2.6

2.7

39.2

2.3

50.9

3.6

62.6

4.9

78.1

5.9

83.9

5.4

89.6

4.8

91.0

4.3

93.2

4.0

95.4

3.8

97.0

3.4

97.9

3.2

98.4

3.3

98.8

3.3

99.0

3.4

99.1

3.4
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Page 21

Table 10.

Comparative Data from OECD 301B CO2 Evolution Test on EO/PO Alkoxides

Alkoxide % ThCO2

1 4 7 11 14 18 21 25 28

SAFOLTM 23-2EO-4PO 4a0.3 18.3 49.7 76.6 86.9 93.2 95.2 97.0 95.7

SAFOLTM 23-5EO-4POb0.5 21.8 53.5 73.1 86.2 91.1 94.4 95.2 96.1

SAFOLTM 23-5EO-5POc2.5 9.8 32.2 61.1 77.4 86.9 89.2 86.2 87.7

SAFOLTM 23-5EO-6POd0.0 8.9 36.5 63.8 80.9 87.1 87.6 85.1 86.1

aBMG report number 451/f-03

bBMG report number 638/e-02

cBMG report number 451/a-03

dBMG report number 451/b-03

Table 11.

Removal of ALFOTERRA® Surfactants in Semi Continuous Activated Sludge (SCAS) Test

Days

% DOC Loss

1 2 3 4 9 11 14 15 16 22 Mean ± Std. Dev.

ALFOTERRA®

123-2S 12.8 15.4 30.4 32.7 23.7 15.2 -0.2 16.3 8.5 17.0 17.2 ± 9.8

123-4S 0 0 0 0 0 0 0 0 0 0 0 ± 0

123-8S 0 0 0 0 0 0 0 0 0 0 0 ± 0

145-2S 20.4 26.9 39.5 37.7 37.1 29.9 24.1 22.9 13.3 17.9 26.9 ± 8.9

145-4S 0 0 0 0 0 0 0 0 0 0 0 ± 0

I12-3S 0 0 0 0 0 0 0 0 0 0 0 ± 0

C12 LAS 98.2 93.7 94.3 -- -- -- -- 100 100 -- 97.5 ± 2.8

ABS 0 0 0 0 0 0 0 0 0 0 0 ± 0
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Page 22

Table 11A.

SCAS Data – MBAS Loss

ALFOTERRA® Surfactant % MBAS Loss

123-2S 99.8

123-4S 87.3

123-8S 51.9

145-2S 97.0

145-4S 82.8

I12-3S 88.4

C12 LAS 99.8

ABS 37.7

1. MBAS analysis done once on day 25 of SCAS Test
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Appendix 
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