Reaction mass of perfluoro(dimethyl - N - Butylamine ) and perfluoro (methyl - di - N - propylamine) and perfluoro (dimethyl - N - propylamine and 2,2,3,3,5,5,6,6, octafluoro-4-(trifluoromethyl)morpholine and perfluoro-N-pentane

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Data from guideline studies under GLP or ISO 17025

Justification for type of information:

MTDID 22327 is a member of the Perfluorinated Organic Chemicals, C5-C18, category. Unlike most members of the category, MTDID 22327 is a UVCB consisting mostly of perfluoro-N-methylmorpholine, a mixture of C5-C7 perfluoroamines, and mixed perfluorohexanes. However, all of these chemicals stem from the same manufacturing process, have similar physicochemical properties including high vapor pressure and low water solubility relative to the hydrocarbon analogs (e.g., hexanes v. perfluorohexanes), and also lack any chemically reactive groups, which forms the technical basis for the category. Members of this category are fully fluorinated, meaning that fluorine, rather than hydrogen, is bonded to all carbon atoms in the molecule. Fluorine is the most electronegative of the elements (fluorine has an electronegativity of 3.98 on the Pauling scale, as compared to 2.55 for carbon, 3.04 for nitrogen or 2.20 for hydrogen). This electronegativity is expected to dominate over all other aspects of substance chemistry and is the underlying basis for similarity of substances in this category. For example, strong electron withdrawing in perfluorinated tertiary amines results in a molecule with essentially no lone pair influence, and which has chemistry more similar to a branched, perfluorinated alkane than any other structure. Because these substances exhibit similar physicochemical properties they can be considered to constitute a chemical category. The data gap for partition coefficient can therefore be addressed by many-to-one read-across between category members.

See section 13 for a fuller discussion of the category approach.

Reason / purpose for cross-reference:

other: composition of substance

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs and grouping of chemicals

Version / remarks:

May/July 2008

Deviations:

no

GLP compliance:

no

Remarks:

Source studies were GLP or ISO 17025 compliant

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Readacross is from category members:
Perfluoro-N-methylmorpholine, PMM, CAS# 382-28-5
reaction mass of perfluoro (methyl - di - N - propylamine) and mono (perfluoro ethyl), di (perfluoro-n-propyl) amine and tri (perfluoro-n-propyl) amine and perfluoro N-methyl N-isopropyl n-propylamine and perfluoro N-methyl, Nisopropyl butamine, MTDID 50908, EC# 920-778-3
Perfluorohexanes, PFHx, CAS# 1064697-81-9

Type:

log Pow

Partition coefficient:

4.3

Temp.:

23 °C

Remarks on result:

other: Constituent 2,2,3,3,5,5,6,6-octafluoro-4-(trifluoromethyl)morpholie

Remarks:

read across from category member PMM

Type:

log Pow

Partition coefficient:

6.14

Temp.:

25 °C

Remarks on result:

other: Constituent 1,1,2,2,3,3,3-heptafluoro-N-(heptafluoropropyl)-N-(trifluoromethyl)propan-1-amine (isomers)

Remarks:

read across from category members MTDID 50908

Type:

log Pow

Partition coefficient:

5.46

Temp.:

25 °C

Remarks on result:

other: Constituent 1,1,2,2,3,3,4,4,4-nonafluoro-N,N-bis(trifluoromethyl)butan-1-amine

Remarks:

read across from category member MTDID 50908

Type:

log Pow

Partition coefficient:

5

Temp.:

23.3 °C

Remarks on result:

other: Constituent tetradecafluorohexane (isomers)

Remarks:

read across from category member PFHx

Experimental partition coefficient data are available for two constituents of MTDID 22327 (perfluoromethylmorpholine, PMM) and (perfluorohexanes; PFHx). In addition, two constituents are common to MTDID 22327 and MTDID 50908. The four constituents described have the highest typical concentrations (>1%) in MTDID 22327. Average Kow values are not reported in all of the source studies. Individual Kow ratios are reported below, with average Kow calculated where necessary

Table, Kow values from source studies

n-octanol: water volume ratio	replicate	PMM	MTDID 50908 Components A and H¹	MTDID 50908 Component D²	PFHx
1:1	1	21300	1520000	315000	86200
	2	21100	1550000	331000	102000
1:2	1	20400	1330000	288000	98800
	2	22600	1330000	276000	108000
	3³	─	1120000	214000	─
2:1	1	outlier, disregarded	1340000	280000	125000
	2	21800	1450000	317000	106000
	3³	─	1420000	288000	─
average Kow		21400	1380000	289000	104000

1, data for unresolved isomeric mixture of constituent 1,1,2,2,3,3,3-heptafluoro-N-(heptafluoropropyl)-N-(trifluoromethyl)propan-1-amine and impurity 1,1,2,2,3,3,3-heptafluoro-N-(1,1,1,2,3,3,3-heptafluoropropan-2-yl)-N-(trifluoromethyl)propan-1-amine

2, constituent is 1,1,2,2,3,3,4,4,4-nonafluoro-N,N-bis(trifluoromethyl)butan-1-amine

3, Only two replicatate were done for PMM and PFHx

Conclusions:

Log n-octanol:water coefficient for components of MTDID 22327 ranged from 4.3 - 6.14 at ca. 23 - 25 °C. The predominant constituent had the lowest measured measured log Kow.

Executive summary:

The Log n-octanol:water coefficient of MTDID 22327 was determined using a category approach wherein the coefficients of known constitituents are used to define the range. The resulting range was 4.3 to 6.14 at ca. 23 - 25 °C. The predominant constituent had the lowest measured log Kow.

The validity of this approach to categorically group these types of substances was determined to be reliable with restrictions based on the similarity of chemical functional groups, molecular weights, water solubilities, and vapor pressures. Since the source data are for constituents of MTDID 22327, they provide the best estimate of the range of partition coefficient for MTDID 22327. The source data are from GLP-compliant or ISO 17025-compliant studies which used national standard test guidelines, and they are considered reliable or reliable with restriction. This study is pertinent to the fate of MTDID 22327 and may be used for Risk Assessment, Classification & Labelling, and PBT Analysis.

Description of key information

Log n-octanol:water coefficient for components of MTDID 22327 ranged from 4.3 - 6.14 at ca. 23 - 25 °C. The predominant constituent had the lowest measured log Kow.

Additional information

The Log n-octanol:water coefficient of MTDID 22327 was determined by read-across using category members which are constituents of MTDID 22327 to define the range. The resulting range was 4.3 to 6.14 at ca. 23 - 25 °C. The predominant constituent had the lowest measured log Kow. Since the source data are for constituents of MTDID 22327, they provide the best estimate of the range of partition coefficient for MTDID 22327.  The source data were collected in guideline studies and are GLP- or ISO 17025-compliant. The read-across is considered reliable with restrictions. Please see IUCLID section 13 for the category justification and a matrix of physicochemical data for members of the Perfluorinated Organic Chemicals C5-C18 category.