CONFIDENTIAL

Title ASSESSMENT OF THE REMOVAL OF DUOMEEN 218i IN BIOLOGICAL TREATMENT

SYSTEMS THROUGH READ ACROSS.

To E. Perez (ANSC Chicago)

Author C.G. van Ginkel and R

. Geerts

Doc. No F 140 55 CG

Date 02

- 05

- 2014

Introduction

Duomeen 218i is a N,N-dialkyl propylene diamine synthesized with isooctadecanoic acid. AkzoNobel Surface Chemistry would like to submit an US chemical notification for this fatty amine derivative. Duomeen 218i is chemically similar to Duomeen 2HT, for which data on its behaviour in activated sludge plants (biological treatment) already exists. The fate of organic substances in biological wastewater treatment systems is mainly determined by their biodegradability, capacity to adsorb, and volatility. Test results obtained with Duomeen 2HT in a continuously-fed activated sludge (CAS) test (OECD 303), information on the biodegradability, potential to adsorb, and volatility of both fatty amines are used to assess the removal of Duomeen 218i in biological treatment systems (read across).

Physical and chemical properties

Table Henry’s law constants and log Koc values for the N,N-dialkyl propylene diamines calculated with EPIsuite (US EPA, 2013). Values of log Koc were estimated from log Kow values of the protonated molecule.

Name Log Koc (l/kg) Henry’s law constant (atm. m 3 mol -1 )

Duomeen 218i a 10.0 (MCI) 9.7 (log Kow) 6 10
- 4

Duomeen 2HT a

, b 10.4 (MCI) 9.8 (log Kow) 4 10

- 4

a structures in figure

a calculated by assuming octadecyl chains

Substances with Henry’s law constants of <10 -3 atm. m 3 mol -1 do not volatilize (Table). Loss of both fatty amine derivatives to air can therefore be excluded. The potential to adsorb of both N,N-dialkyl propylene diamines is also comparable (Table). The log Koc values strongly indicate that both substances have a high potential to adsorb onto activated sludge particles.

Biodegradability

Mono branching with a methyl group at the end of both alkyl chains is the only difference in structure compared to Duomeen 2HT (Figure). The perception that branched-chain alkyl chains are difficult to degrade is primarily based on the recalcitrance of substances with multi branched alkyl groups. Nonetheless several bacterial strains can degrade pristane, an alkane with multiple methyl branching, easily. The oxidation of pristane has been shown to be common and many microorganisms have acquired pathways for assimilation of branched Environmental Chemistry PO Box 9300

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carboxylic acids derived from this alkane (Pirnik, 1977; Watkinson and Morgan, 1990). Microorganisms degrading isoprenoids (e.g. citronellol) and methyl branched amino acids (e.g valine) are also very common. Isoprenoids are characterized by methyl-branched molecular structures derived from isoprene. Several bacteria, particularly Pseudomonas sp. utilize these compounds as sole carbon source (Cantwell et al , 1978 and Díaz Pérez et al. 2004). The branched fatty acid, isobutyric acid (2-methyl-propionic acid) is an intermediate in the microbial degradation of valine (dePaul Marshal and Sokatch, 1972). Amino acids and isoprenoids are readily biodegradable. The ready biodegradability of mono branched alkyl sulphates has been demonstrated (Battersby et al , 2000). Microorganisms capable of degrading 2-butyloctyl sulphate (mono-branched) as sole carbon and energy source were isolated from activated sludge of a plant treating primarily domestic wastewater (Ellis et al

, 2004). The ability of microorganisms to utilize many organic compounds with mono branching (alkanes, isoprenoids, carboxylic acids and amino acids) demonstrates that enzyme recruitment results in a high biodegradation potential of these substances. Substances with one alkyl especially methyl branching along the alkyl chain are therefore considered as rapidly and completely biodegradable like their linear counterparts.

Removal of Duomeen 2HT in biological wastewater treatment plants (OECD 303)

The removal of Duomeen 2HT in biological treatment plants was assessed in CAS unit fed with domestic wastewater spiked with the fatty amine derivative (AkzoNobel, 2010). The CAS tes was performed according to the OECD 303 test guideline in compliance with GLP. Duomeen 2HT was exposed to activated sludge maintained by addition of domestic wastewater in the CAS test. The mean carbon removal percentage of calculated over 15 measurements of the test was 104±1%. Formation of water soluble compounds during biological treatment of Duomeen 2HT can therefore be excluded. The mean removal percentage of Duomeen 2HT from the influent was >99.9%. Mean removal percentages of Duomeen 2HT through adsorption onto sludge assessed was 1.3% demonstrating that Duomeen 2HT is primarily removed by biodegradation.

Read across

Negligible evaporation and comparable potential to biodegrade and adsorb of Duomeen 2HT and Duomeen 218i demonstrate that read-across is justified. Duomeen 218i is based on read-across expected to be removed from wastewater by >99.9% primarily as the result of biodegradation. Less than 2% of the Duomeen 218i entering a wastewater treatment facility is expected to be removed by adsorption.

References

x Akzonobel (2010) Determination of the primary and ultimate biodegradation of N,Ndi(hydrogenated tallow-alkyl)-1,3-propanediamine in a continuously-fed activated sludge unit treating domestic wastewater. Report doc. 2.421.206 T09066 CAS.

x Battersby NS, Kravetz L, Salanitro JP (2000) Effect of branching on the biodegradability of alcohol-based surfactants, In 5th World Surfactant Congress. Federchimica, Milan, Italy pp 1397-1407.

x Cantwell SG, Lau EP, Watt, DS and Fall RR (1978) Biodegradation of acyclic isoprenoids by Pseudomonas species. Journal of Bacteriology, 135 (2). 324-333.

x dePaul Marshall V, Sokatch JR (1972) Regulation of valine catabolism in Pseudomonas putida J Bac 110 (3) 1073-1081.Page 3 of 4

x Diaz Perez AL, Zavala-Hernandez AN, Cervantes C, and Campos Garcia AJ (2004) The gnyRDBHAL cluster is involved in acyclic isoprenoid degradation in Pseudomonas aeruginosa . Applied and Environmental Microbiology, 70(9), 5102-5110.

x Ellis AJ, hales SG, Ur-Rehman GA and White GF (2002) Novel alkylsulfatases required for biodegradation of the branched primary alkyl sulfate surfactant 2-butyloctyl sulfate. Appl Environ Microbiol 68 31-36.

x U.S. Environmental Protection Agency (2013). EPIWEB v 4.1. US EPA. [2012]. Estimation Programs Interface SuiteTM for Microsoft® Windows, v 4.1. United States Environmental Protection Agency, Washington, DC, USA.

x Watkinson RJ and Morgan P (1990) Physiology of aliphatic hydrocarbon-degrading microorganisms. Biodegradation 1 79–92.Page 4 of 4

Figure Chemical structures of Duomeen 2HT (left) of Duomeen 218i (right).