Terphenyl

Endpoint summary

Additional information

Biodegradation in water:

The available studies – although not all with GLP declaration – are all of good quality, using standard protocols. All studies are used in a Weight of Evidence approach to support the final conclusions.

 

Indeed all aquatic biodegradation tests show that terphenyl mixtures are not ready biodegradable. Since the substance is composed of three main constituents: o-, m- and p-terphenyl, these were also evaluated seperately. Looking at the individual terphenyls m-terphenyl is moderately degradable, o-terphenyl displays a certain level of biodegradation but p-terphenyl appears to be rather persistent. On a terphenyl 'mixture' level it could therefore be concluded that Terphenyl mixtures are persistent in water. On a constituent level however, this can be concluded for p-terphenyls, but for o-terphenyl and definitely for m-terphenyl biodegradation does occur and these constituents should not be regarded as persistent.

Biodegradation in soil:

The simulation test in soil was performed on Therminol – a mixture of terphenyl, quatraphenyl and polyphenyl. The disappearance of these individual groups was measured during 32 weeks. Results show that the smallest compound, Terphenyl, was degraded substantially by means of biological degradation with half times – dependent upon soil quality – between 8-28 weeks.

It is concluded that terphenyl mixtures are slowly degradable in soil.

Overview of the relevant studies:

test	ref	Test substance	Endpoint		interpretation	Test quality
SCAS	1048006	Therminol 88 (o, m, p)	Disappearance	12+/-7 %	Persistant	Not GLP
SCAS	AC75SS15 1976	Therminol 88 (o, m, p)	Disappearance	12%	Persistant	Not GLP
CO2 evolution	ES82SS22 1982	MCS1980 (read-across)	CO2 production (16-30d)	<10% ultimate degradation 100% transformation	Degrades into more persistent intermediates	Not GLP
CO2 evolution- commercial inoculum	ES83SS42 1983	m-terphenyl     o-terphenyl, p-terphenyl	CO2 production (55d)	38% (>25% of theoretical (2-3 days for adaptation))   20% (= 20% of theoretical) 10% (< 20% of theoretical)	Moderate     Moderate Persistent	Not GLP
CO2 evolution Adapted inoculum	ES91SS07 1991	p- terphenyl	CO2 production (42d)	At 11 mg/l: 9% of theoretical, 81% recovery At 21 mg/l: 8 % of theoretical, 78% recovery	Persistent	GLP
River die away	ES83ss35 1983	o- , m- terphenyl   p-terphenyl	Disappearance	Starts after 16-28 d adaptation   No degradation within 42 d	Moderate     Persistent	Not GLP
Screening in soil - simulation	803206, 1989	Therminol: Terphenyl	Disappearance	t1/2 = 8.1 – 28.4w	Mainly biological degradation	GLP
Photolysis	ES 83 SS 33	o-, p-terphenyl m terphenyl	Disappearance Disappearance	0% decrease after 29 days About 20% decrease (29 days)	No photolysis No significant photolysis	Not GLP