Table 1.

Sample list of a subset of well-established obesogens with their partitioning coefficients, half-life, and molecular weight (g/mol). The octanol/water partitioning coefficient is measured using the log K_ow value, which indicates the partitioning of a chemical between octanol and water. In these experiments, octanol is used to mimic fat and other hydrophobic components in biological systems. A partitioning coefficient level greater than 1 indicates low solubility in water

Obesogen Source	Obesogensa	Chemical Characteristics*
		Partitioning (Log Kow) b	Half-life (hours)c	Size (g/mol)
Industrial Chemicals	Bisphenol A (BPA)	3.32	5.3d [10, 11]	228.291
	Bisphenol A diglycidyl ether (BADGE)	~ 3.84	120e [12]	340.419
	Bisphenol S (BPS)	~ 1.65	6.93 [13]	250.268
	Firemaster 550 (FM550)	8.80–11.95f	Unknown [14]	549.923
	2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47)	6.81 ± 0.08 [15]	664 daysg	485.795
	3,3′,4,4′-Tetrachlorobiphenyl (PCB-77)	6.72	152–186 [16]	291.980
	Mono-(2-ethylhexyl) phthalate (MEHP)	4.92h	4.4–6.6i	278.348
	bis(2-ethylhexyl) phthalate (DEHP)	7.60	5j	390.564
Biocides	Dichlorodiphenyl-trichloroethane (DDT)	6.91	10.6k	354.476
	Tributyltin (TBT)	3.90–4.90 [17]	23–30 days [18]	290.058
	Triphenyltin (TPT)	4.19l	3 days	385.478
Pharmaceuticals	Diethylstilbestrol (DES)	5.07	2–3 days [19]	268.350
	Estradiol (Estrogen steroid Hormone)	4.01	3 days	272.388
Pollutant	Dioxin	6.80	5–8 years	321.970
Smoking	Nicotine	1.17	1–4m	162.236

Sources

^*Values of partition coefficients and half-lives might differ from those in this table because of variations in the study such as the location the study was conducted, type of tissue, biphasic pattern, initial dosage, temperature, salinity and pH.

^aThe obesogens discussed are well-established obesogens that have been used in various studies.

^bAll values of log K_ow were reported at 25°C and at a pH of 7 unless stated otherwise.

^cAll estimated half-life values reported were conducted on studies in human based models unless stated otherwise.

^dBPA data are not consistent with the current consensus that BPA exposures are both rapidly cleared and almost entirely related to food intake. Instead, it appears plausible that there is substantial nonfood exposure, accumulation in body compartments with long elimination times, or both [3].

^eBisphenol A diglycidyl ether based on Hydrolysis in Water.

^f2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis (2-ethylhexyl) tetrabromophthalate (TBPH) are the two major additive Brominated flame retardants (BFRs) in Firemaster 550. [16].

^gTetrabromodiphenyl ether (BDE-47) has two phases of elimination. The first phase of elimination is where the majority of the BDE-47 is eliminated from the body (67%), and the remaining BDE-47 is eliminated during the terminal phase. Additionally, elimination, both whole-body and from individual tissues, is biphasic due to varying initial and terminal phase lengths in different tissues. Since BDE-47 is highly lipophilic its terminal phase was primarily dictated by adipose tissue and skin [21].

^hMEHP was estimated from n-octanol: water coefficient (K_ow) by the algorithm from Poulin and Krishnan (1993). A log K_ow of 4.92 was estimated based on the chemical structure for nonionized MEHP.

ⁱSingle administration of MEHP in a rat (0.4 g/kg) resulted in plasma concentrations of 84.1 +/− 14.9 micrograms/ml 3 h after dosing; the half-life of MEHP was 5.5 +/− 1.1 h. [22].

^jAfter an absorption and distribution phase of 4 to 8 h, half-life times of excretion in the first elimination phase were approximately 2 h; Half-life times in the second phase—beginning 14 to 18 h post dose—were 5 h for MEHP [23].

^kFemale rats were dosed orally with (14) C-ring-labeled p,p’-DDT during pregnancy or lactation. Average half-life was 10.6 h in tissues and in the fetus.

^lTriphentylin Chloride was used to find the log K_ow.

^mNicotine’s half-life in the initial phase is reportedly about 2–3 min and the half-life in the terminal phase averages about 2 h.

Note: All partitioning coefficient values > 1 indicate lipophilic properties (bold). Half-life with strong indication of biphasic pattern (bold). Non-asterisk and cited chemical characteristics were obtained from the U.S. National Library of Medicine Open Chemistry Database and the International Programme on Chemical Safety.