Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

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