Benzene, mono-C11-13-branched alkyl derivs.

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

other: expert assessment

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: European Chemicals Agency (2008). Guidance on information requirements and chemical safety assessment - Chapter R.7c: Endpoint specific guidance - R.7.12: Guidance on Toxicokinetics. 145- 214.

Conclusions:

Significant bioaccumulation potential based on this study report

Description of key information

No measured data were available for any of the assessed toxicokinetic properties for BAB, however discussion could be based on results from toxicity studies and in a second instance on physico-chemistry data. Experimental toxicokinetic data were available from a reliable analog and some toxicological data were available for another analog , and were consistent with what could be deduced for BAB. Thanks to this approach, appropriate and precise conclusions could be reached, which are the following:

Absorption:      

Oral: BAB:significant absorption demonstrated by systemic effects after ingestion.Via quantified data on an analog: >75% absorbed.

Dermal: BAB: no data, slow/low absorption anticipated from physico-chemical data.Via quantified data on an analog: 8-13% absorbed.

Inhalation: BAB: no data, significant absorption anticipated as for oral route. Via quantified data on an analog: >75% absorbed.

Distribution: 

BAB: likely (based on effects) to gastro-intestinal tract (incl. liver), male reproductive system (prostate, seminal vesicles, testes), and temporarily to the kidneys. Possibly to adrenals and thymus (or stress effect).

Via data on an analog : persists in fat tissue and metabolism/excretion/secretion organs (liver, bile duct, Harderian, preputial, clitoral, lachrymal, stenos and salivary glands) ; present inpituitary and blood sinuses. Same NOAEL after 3.5-fold longer exposure suggests no toxicologically relevant bioaccumulation of toxic compounds in target organs.

Metabolism:          

BAB: likely (based on effects) by liver.

Via data on analogs: rapid but incomplete liver metabolism into a variety of compounds; possibly carboxylic acid and/or thioamide metabolites;similar extent of metabolism by all routes; oxidative metabolism by cytochrome P450 is less active when branching increases(as in BAB).

Excretion:                

BAB: urinary not likely for unchanged parent (based on low solubility).

Via 2PD: extensive metabolization before urinary excretion (major route), largely incomplete metabolization before fecal excretion(minor route). Possible exhalation not reported.

Key value for chemical safety assessment

Bioaccumulation potential:

high bioaccumulation potential

Absorption rate - oral (%):

75

Absorption rate - dermal (%):

13

Absorption rate - inhalation (%):

75