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Schaeffer, John

From: Boethling, Bob

Sent: Tuesday, July 16, 2013 4:22 PM

To: Lin, Chuantung; Schaeffer, John

Cc: Lewis, Paul; Williamson, Tracy; Christian, Myrta

Subject: RE: 22527-63-5 HPV 3 submissions -- M/FP BP VP WS Log P biodeg

I reviewed the ready biodegradation study for Benzoflex 1046 and first, thanks to Daniel for pointing out the mixture 

issue. This would not be evident from the ready biodeg test report’s minimal characterization of the test material. It’s 

easy to see from the biodegradation curves in the report that the degradation process follows a biphasic pattern. This 

could be easily explained by degradation of one part of the molecule (say the benzoic acid, released by initial hydrolysis), 

followed by degradation of other part(s), e.g. the alcohols. Of course there are two ester groups, and several different 

molecules in the initial mixture, so in the end you are interpretationally challenged. The submitter says the data show 

the substance is readily biodegradable. Given the high observed degradation (94% ThOD) it’s unlikely that a significant 

amount of starting material remained undegraded. But if there is a need to be sure, for example if the different 

components have very different toxicity profiles, then the study would need to be repeated using purified components. 

Here’s a rule of thumb. Do not test mixtures (with very few exceptions). 

Robert Boethling, PhD 

Exposure Assessment Branch 

US EPA, Office of Pollution Prevention and Toxics 

1200 Pennsylvania Ave, NW (7406M)

Washington, DC 20460 

202-564-8533 (P) 

202-564-8892 (F) 

[EPI Suite] http://www.epa.gov/opptintr/exposure/pubs/episuite.htm 

 

[FatePointer] http://esc.syrres.com/fatepointer/search.asp

From: Lin, Chuantung 

Sent: Tuesday, July 16, 2013 11:00 AM 

To: Schaeffer, John; Boethling, Bob 

Cc: Lewis, Paul; Williamson, Tracy; Christian, Myrta 

Subject: RE: 22527-63-5 HPV 3 submissions -- M/FP BP VP WS Log P biodeg 

Hi John, 

I have reviewed the submitted test data (Freezing Point, Boiling Point, Vapor Pressure, Log P, and Water 

Solubility endpoints) for the HPV3 chemical, 22527-63-5. All these data and test methods are adequate and 

acceptable to EPA. However, it needs to be noted that the test sample used for these testings was not a 100 

% pure substance. Instead, it was a mixture chemicals which contained: 

1) Propanoic acid, 2-methyl-, 3-(benzoyloxy)-2,2,4-trimethylpentyl ester [22527-63-5] (68.8 %) - This 

chemical is the titled HPV3 Test substance

2) 1,3-Pentanediol, 2,2,4-trimethyl-, 1 ,3-dibenzoate [68052-23-3] (19.5 %) 

3) 2,2,4-trimethyl-1 ,3-pentanediol, diisobutyrate [6846-50-0 ] (7 %) 

4) Misc. esters (4.2 %) 

5) Volatiles (0.5%) 
2

If I remembered correctly that ICB had provided comments before on the proposed test sample (a mixture of 

three chemicals (#1 -#3) listed above) that the Sponsor proposed to be used for the HPV3 Test Rule 

requirements for all these five endpoints. However, I am not sure whether EPA has finally agreed and 

accepted on such approach (i.e. using the mixture of the three chemicals) to fulfill the testing requirements 

for this HPV 3 Test Chemical. 

Please let me know if you have other question. 

Thanks! 

Daniel 

From: Schaeffer, John 

Sent: Wednesday, June 26, 2013 9:59 AM 

To: Lin, Chuantung; Boethling, Bob 

Cc: Lewis, Paul 

Subject: 22527-63-5 HPV 3 submissions -- M/FP BP VP WS Log P biodeg 

Daniel, Bob, good morning. 

Attached for your respective reviews are physical-chemical properties endpoint studies and a ready biodegradation 

study for the HPV3 test rule chemical Propanoic acid, 2-methyl-, 3-(benzoyloxy)-2,2,4-trimethylpentyl ester (CASRN 

22527-63-5). The submissions contain the following: 

Physical Chemical Properties 

• Freezing Point (OECD 102) 

• Boiling Point (ASTM E 1719-05) 

• Vapor Pressure (ASTM E 1782-08) 

• Octanol/Water Partition Coefficient (ASTM E 1147-92) 

• Water Solubility (40 FR 799.6784) 

Environmental Fate – Ready Biodegradation 

• Ready Biodegradation (ISO 9408:1999(E)) 

Please review these for data adequacy/acceptability by EPA. Please also let me know when we can anticipate receiving 

your reviews. 

Thank you. 

John Schaeffer 

Senior Biologist 

USEPA/OPPT/CCD/CITB 

1201 Constitution Ave, NW 

Washington, DC 20460 

Mail Code: 7405M 

Phone: 202-564-8173