Dibutyl phthalate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Adequacy of study:

other information

Test organisms (species):

Nitocra spinipes

Test type:

static

Total exposure duration:

96 h

Test temperature:

21 (+/-1) degrees Celsius

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Executive summary:

The study (Linden et al 1979, Bengtsson & Tarkpea 1983) measured the EC 50 value for DIBP concerning Nitocra spinipes.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Adequacy of study:

other information

Qualifier:

according to guideline

Guideline:

other: DIN 38412, part 11

Test organisms (species):

Daphnia magna

Test type:

static

Total exposure duration:

24 h

Test temperature:

21 degrees Celsius

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

2.5 mg/L

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

20 mg/L

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

7.4 mg/L

Nominal / measured:

nominal

Basis for effect:

mobility

Remarks on result:

other: calculated by sine transform

Executive summary:

The study (Hüls 1986) measured and caculated EC values for DIBP concerning daphnia magna.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Adequacy of study:

other information

Test organisms (species):

Palaemonetes pugio

Details on test organisms:

Adult grass shrimp were collected from vegetated shorelines along Santa Rosa Sound near the Environmental Research Laboratory at Gulf Breeze (ERL/GB), FL, by using a dip or sweep net. They were held at ERL/GB for one to four weeks in flowing seawater and fed a flake-type fish food four to five times per week.

Test type:

other: static, flow-through

Water media type:

saltwater

Total exposure duration:

96 h

Test temperature:

waterborne exposure: 22 +/- 1 C
sedimental exposure: 25 +/- 1 C

pH:

7.8-8.2

Dissolved oxygen:

>70% saturation

Salinity:

"salinity was that of incoming seawater"

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

1 000 µg/L

Nominal / measured:

nominal

Remarks on result:

other: water-source exposure

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

10 other: mµ/kg

Nominal / measured:

nominal

Remarks on result:

other: sediment-source exposure

Details on results:

96-hr LC50s for grass shrimp in water-source: DBP caused no deaths at 1,000 µg/L, the highest concentration tested.

Sediments contaminated with DBP at 10,000 µg/kg were not lethal to test populations of grass shrimp; therefore, no higher concentrations
were tested.

In the higher test concentrations during sediment-source tests with DBP, grass shrimp clung to the sides of test containers above the sediment/water interface, presumably in an attempt to avoid contact with highly contaminated sediments or water concentrations established at the sediment-water interface as chemical leached from the sediment. Detailed behavioral observations would be necessary to quantify avoidance behavior as a test endpoint.

Conclusions:

The highest concentrations of DBP, 1,000 µg/l for water-source expsoure and 10,000 µg/kg for sediment-source exposure (other tested concentrations are not documented in study report), caused no deaths of grass shrimps.

Executive summary:

The study examined the effects of several chemicals on grass shrimps. Only those of DBP are documented here. The study researched also the effects on amphioxus, but because non of the tested chemicals was DBP, this part of the study is neglected here.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Adequacy of study:

other information

Test organisms (species):

Daphnia magna

Details on test organisms:

Water flea (Daphnia magna) brood stock was obtained from the Environmental Research Laboratory-Duluth. MN, U.S. EPA. The brood stock was maintained at a temperature of approximately 20 C on a diet consisting of a mixture of finely ground traut chow and baker's yeast.

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test temperature:

20.9 +/-0.1 C; n=3

Dissolved oxygen:

unfed: 93.3 +/-1.5 C; n=9

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

3.7 mg/L

For results: s. table 5

Conclusions:

In this study a 48 hr LC50 of 3.70 mg/l was obtained with Daphnia magna.

Executive summary:

The study tested 22 chemicals for their acute (or chronic) toxicity to freshwater organisms. Only the study in DBP, which was only tested on daphnia magna, is documented here.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Conclusions:

Measured effect concentrations [mg/l]:

EC50 (48h): 0.76 (Chironomus plumosus) - 5.2 (Daphnia magna)
EC50 (24): 17 (Daphnia magna)
LC50 (96h): 0.8 (Mysidopsis bahia) - 2.1 (Gammarus pseudolimnaeus)
LC50 (24h): 8 (Artemia salina)

Executive summary:

Short-term toxicity of DBP to aquatic invertebrates

 

No.	Species	Result(mg/l)95%C.I.	Method	Reference
1	Daphniamagna	3.4 (48 hEC50)	EE92/69	Hüls(1994b)
2	Daphniamagna	5.2 (4.7-5.6) -(48hEC50)	Other	McCarthyandWhitmore(1985)
3	Daphniamagna	17 (24 hEC50)	Other	Kühnetal.(1989)
4	Daphniamagna	3.4 (3.1-3.8) -(48hEC50)	EG&GBionomics(1982)	CMA(1984)
5	Chironomusplumosus	0.76 (48 hEC50)	Other	Streufertetal.(1980)
6	Mysidopsisbahia	0.8 (0.6-0.9) -(96hLC(I)50)	Other	EG&GBionomics(1984a)
7	Nitocraspinipes	1.7 (1.3-2.2) -(96hLC(I)50)	Other;brackishwater	Lindénetal.(1979)
8	Gammaruspseudolimnaeus	2.1 (96 hLC50)	APHA(1971)	MayerandSanders(1973)
9	Paratanytarsusparthenogenetica	5.8 (96 hEC50)	Other	EG&GBionomics(1984b)
10	Artemiasalina	8(24hLC50)	Other;seawater	Hudsonetal.(1981)

Reference 6

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well documented and scientifically acceptable, but lacking guidelines

Principles of method if other than guideline:

No guideline specified, cf. "Any other information on material and methods" for details.

GLP compliance:

not specified

Test organisms (species):

Artemia sp.

Details on test organisms:

Brine shrimp larvae. Encysted embryos (San Francisco Bay Brand, Newark, CA) were sterilized and stored frozen (-20°C) in 5 g lots. Synchronously hatched larvae were prepared for toxicity, uptake and metabolism experiments. Dry weights of larvae/ml were determined by filtering 100 µl of the suspension of larvae at ~10^3/ml through Miracloth, washing with cold distilled water and transferring the larvae to a tared flask for lyophillization.

Test type:

static

Water media type:

saltwater

Total exposure duration:

48 h

Remarks on exposure duration:

metabolism experiment: 2, 4, 8h

Test temperature:

~30°C

Reference substance (positive control):

yes

Duration:

24 h

Dose descriptor:

other: LD50

Effect conc.:

30 other: µM (8 ppm)

Di-n-butyl phthalate in the ppm concentration range had a pronounced acute toxic effect when added to the artificial sea water environment of synchronously hatched Artemia larvae. Fig 1 shows the percent mortality after a 27 h incubation as a function of the DNBP concentration employed. DNBP incubated with the encysted embryos during any span of the 16 hour period before hatching had no effect on hatching or survival of the hatched embryos, provided the DNBP was removed prior to hatching (data not shown). The 24 hour post hatching interval was a convenient time over which to judge acute toxicity since little mortality was observed until after that period in unfed control larvae. Fig 2 shows that even at the highest concentrations employed, significant mortality required a 6-8 h incubation period. It should be noted that the highest concentrations employed are near the solubility limit for DNBP. Although we have not precisely determined the solubility of DNBP in artificial sea water, it is not surprising to find it considerably below the solubility in distilled water. Neither n-butanol nor mono-n-butylphthalate exhibited any toxic effect at concentrations up to 100mM when tested as described for DNBP.

That the lag period prior to the onset of mortality may be due to some extent to the slow uptake of DNBP by the organism is suggested by Fig. 3, which shows the uptake of [14C] DNBP by Artemia larvae as a function of time for several coocentrations. The 6-8 hour plateau appears to reflect the time required for maximum uptake of [14C] DNBP over the concentration range studied. The calculated distribution ratios between the larvae and the sea water for different times during the accumulating phase are shown in Table 1. The distribution between sea water and larvae achieved after 6-8 hours incubation was similar to that observed between sea water and octanol.

Subsequently the intra-larval radioactivity decreased, reaching 25% of plateau levels after 24 h of continuous exposure (data not shown). The depletion of intra-larval radioactivity after the 6 -8 h period reflects the hydrolysis of the DNBP by enzyme(s) which are formed at this time. Fig 4 shows the separation on thin layer chromatograms of DNBP and its principal hydrolysis product, monon- butyl phthalate, after incubation of larvae with 25 µM [14C] DNBP for 8 and 24 h. This figure clearly shows that there is little hydrolysis during the 6-8 h accumulation phase and suggests the appearance or increase of enzyme(s) which significantly hydrolyze accumulated DNBP between 8 and 24 h. Fig 5 shows the extent of hydrolysis of DNBP by cell-free extracts prepared from dormant encysted embryos (0 hr) and from larvae harvested at 24 (newly hatched), 48 or 72 hr of development. It is clear that the enzyme(s) develop to greater activity during the latter part of this period.

Conclusions:

Di-n-butyl phthalate (DNBP) is toxic to synchronousiy developing larvae of the brine shrimp, Artemia. The LD50 for 24 h exposure is approximately 30 µM (8 ppm).

Executive summary:

The study researched the acute toxicity and the metabolism of di-n-butyl phthalate, abbreviated in this study as DNBP. On acute toxicity it predominantly listed it results in figures, not numbers (such as endpoint levels). On metabolism it concludes: "DNBP is concentrated by larvae, and maximal uptake of DNBP precedes the onset of mortality. At the time of maximal uptake, most of the DNBP remains in the form of the diester. By the time of maximal mortality nearly all of the DNBP has been converted to the monoester, n-butanol and possibly other polar metabolities. n-Butanol and mono-n-butyl phthalate directly incubated with larvae were nontoxic when tested in concentrations at which DNBP was toxic. Soluble enzyme(s) extracted from the hatched larvae, but not from the dormant embryos, can convert DNBP to its monoester and n-butanol. The amount of enzyme activity increased with larval development in parallel with the kinetics of acute toxicity. The enzyme may be significant in the developmental program as well as in the mediation or moderation of the toxic effects of DNBP in Artemia larvae."

Reference 7

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well documented and scientifically acceptable, but lacking guidelines

Test organisms (species):

Nitocra spinipes

Details on test organisms:

Harpacticoids play an important, sometimes domtinating, role as food organisms for larval fish and crustacea species, many of which are economically important. N. spinipes is often very numerous, especially on sand bottoms, interstitially or free, and in the phytal. It is an euryhaline and typical brackish water organism and it is found in coastal regions in Europe, Asia, Africa and North America, tolerating salinities from marine to almost linmic conditions. The development passes six nonpelagic metanauplic stages and five copepodid stages. The length of the adult animal is about 0.6 to 0.8 mm. Culturing is simple and is preferably performed in 5 to 25 o/oo salinity. The development from egg to adult takes about two weeks and animals at all developmental stages can be harvested frcm the cultures at any time of the year.

Test type:

static

Water media type:

brackish water

Total exposure duration:

96 h

Test temperature:

20-22° C

pH:

7.8

Dissolved oxygen:

5 mg O2/l

Salinity:

7 o/oo

Reference substance (positive control):

yes

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.3 - 2.2 mg/L

The results of the tests are summarized in Table 3 and are expressed as the 96 hr LC (I)50, i.e. the initial concentration of a substance killing 50 per centof the test organisms during 96 hours. The values are given in mg/l and are determined by the graphical method described by Litchfield and Wilcoxon). The numbers in brackets represent 95 per cent confidence limits. In some instances, the Tables show the range of concentration within which the LC(I)50 occurred, but for which it was not possible to estimate the exact value according to Litchfield and Wilcoxon's method.

None of the listed substances will be thoroughly discussed in this report and the results of the tests with alcohols will be dealt with in detail elsewhere (Bengtsson and Renberg, to be published).

Conclusions:

The measured 96h LC50 was 1.7 (1.3-2-2) mg DBP/l.

Executive summary:

The toxicity of 78 chemicals and pesticide formulations against the bleak, Alburnus alburnus (Pisces) and the harpacticoid Nitocra spinipes has been tested. Only the effects of DBP, which was only tested on nitocra spinipes, are documented here.

Reference 8

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Specific details on test material used for the study:

Chemicals were obtained commercially.

Test organisms (species):

Artemia salina

Details on test organisms:

Brine Shrimp (Artemia salina) eggs were obtained commercially.

Test type:

static

Water media type:

saltwater

Total exposure duration:

24 h

Test temperature:

26°C

pH:

8.3

Salinity:

2% NaCl

Reference substance (positive control):

yes

Effect of Phthalate Esters on Hatching

Fig. 1 shows the number hatched at the various concentrations of DMP (Dimethyl phthalate), DEP(Diethyl phthalate) or DBP(Di-n-butyl phthalate). DBP

had more effect on hatching than DMP or DEP. At 3.7x10^-5 M the number hatched was significantly less (p<0.01) than that of the control.

Effect of Phthalate Esters on Nauplius

Table 1 shows the effect of DMP, DEP or DBP on the mortality of nauplius. DMP and DEP did not effect the death of larvae at the order of 10^-4 M, but DBP had an effect at 3.7x10^-5 M.

Conclusions:

Effects for DBP were shown at 3.7x10^-5M.

Executive summary:

To estimate the toxicity of phthalate esters in fresh-water invertebrates, the effect of phthalate esters on the hatching of Shrimp eggs and the mortality of the nauplius or larvae stage was tested. The toxic order of three phthalate esters was DBP~ DEP >DMP.

Reference 9

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Total exposure duration:

24 h

Hardness:

Hardness was adjusted to 90, 180, 360, 540 mg/L CaCO3

Test temperature:

15, 20, 25, 30 °C

Nominal and measured concentrations:

Five concentrations (0, 2.59, 5.18, 6.90, 10.35 mg/L) of DBP, nominal

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

10.35 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Effect of temperature, humic acid and temperature on the EC50 value:

It can be seen that 24 h-EC50 of DBP decreased with temperature. Enhancement of temperature may cause the increase of growth and metabolism rate of Daphnia magna and exchange rate of chemical with the ambient medium. Hence toxicity of DBP

increased. Toxicity of DBP decreased with the increasing concentration of humic acid. Humic acid can complex DBP, thus bioavailability of DBP decreased with the decline of free, dissolvable DBP. The value of 24 hr-EC50 became low with

increasing hardness. Hardness of water medium has been shown to affect toxicity of many chemicals including heavy metals and organic pollutants. The mechanisms for the effects of hardness on organic compounds have not been

elucidated clearly. The possible reason is that the change of concentration of Ca2 + and Mg2+ ions caused the change of uptake and distribution of DBP in the organism, which results in the change of toxicity of DBP.It can be seen that 24 h-EC50 of DBP decreased with temperature. Enhancement of temperature may cause the increase of growth and metabolism rate of Daphnia magna and

exchange rate of chemical with the ambient medium. Hence toxicity of DBP increased. Toxicity of DBP decreased with the increasing concentration of humic acid. Humic acid can complex DBP, thus bioavailability of DBP decreased with the decline of free, dissolvable DBP. The value of 24 hr-EC50 became low with increasing hardness. Hardness of water medium has been shown to affect toxicity of many chemicals including heavy metals and organic pollutants. The mechanisms for the effects of hardness on organic compounds have not been elucidated clearly. The possible reason is that the change of concentration of Ca2+

and Mg2+ ions caused the change of uptake and distribution of DBP in the organism, which results in the change of toxicity of DBP.

Validity criteria fulfilled:

yes

Conclusions:

The 24h-EC50 of DBP to Daphnia magna was 10.35 mg/L at 25 °C (approaching its solubility.)

Reference 10

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Specific details on test material used for the study:

Stock solutions were freshly prepared in distilled water for the chemicals with a solubility in water > 1000 mg/liter. Dibutyl phthalate, I-octanol, and pentachlorophenol, which had a limited solubility in water, were tested in three different ways
described below. No pH adjustments were made on the samples tested according to recommendations by A. A. Bulich (personal communication). Registration of the pH showed no extreme value. Color corrections were not necessary for any of these compounds.

Test organisms (species):

Nitocra spinipes

Details on test organisms:

N. spinipes Boeck (Crustacea) is a typical brackish water organism, playing an important role in the food chain of the Baltic Sea. The length of the adult animal is about 0.6-0.8 mm. Culturing in the laboratory (Bengtsson, 1978; Gopalan, 1977) is easily done, and the development from egg to adult stage takes about 2 weeks.

Water media type:

brackish water

Test temperature:

25°C

pH:

7.0 +/-0.5

Salinity:

0.7 +/-0.1%

The results from the test of three different ways of testing compounds with low water solubility are presented in Table 7. Good agreement regarding EC50 values was obtained for 1-octanol and pentachlorophenol when using the different dosing methods. Dibutyl phthalate, on the other hand, dosed through a stock solution in acetone, showed no toxic effect on the bacteria.

Executive summary:

A comparison between the static 96 -hr L50 test with the brackish water harpacticoid Nitocra spinipes and the Microtox (Beckman Instruments, Inc.) screening method has been done. The

relationship between the two bioassays were evaluated for 16 pure and technical chemicals and 11 complex effluents from different types of industries. Investigations concerning pretreatments of three chemicals (dibutyl phthalate, l-octanol, and pentachlorophenol) fairly insoluble in water (less than 1000 mg/liter) have been done. Only the results concerning DBP (s. Table 7) are documented here.

Reference 11

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

In this investigation the locomotor activity of G. pulex was studied under phthalate stress. The aim of the study was to determine the effects of phthalates on overall locomotor activity of G. pulex and the impact of long term exposure on diel activity.

Test organisms (species):

Gammarus pulex

Details on test organisms:

Animals were obtained from a stream in the southem part of Sweden, which has been described previously by Hultin (1971). The animals were acclimated for rive days before the activity was measured. Owing to limitations in the photocell detection system we had to use organisms > 12 mm in length.

Test type:

flow-through

Water media type:

freshwater

Total exposure duration:

10 d

Post exposure observation period:

10 d

Test temperature:

10-12°C

Nominal and measured concentrations:

100, 500 µg/l

Reference substance (positive control):

yes

There was no difference in mortality between phthalate-exposed and non-exposed organisms.

The activity of G. pulex was initially high, reaching a maximum level of around 600 passages/hr (Fig 2). It took between 5 and 10 d for the animals to become acclimatized, afier which their activity stabilized between 50 to 100 passages/hr. G. pulex was expected to show an activity peak after dawn, since the activity center (= the midpoint between onset and termination of activity) lies before dawn

when darkness exceeds 8 hr/24 hr and after dawn when the dark period is of shorter duration. A number of studies have confirmed this in the field (Hultin 1971). During the pre-exposure period, there was a tendency towards higher activity during the day. However, afler 5 d, the diel activity pattem become irregular for exposed as well as non-exposed animals, and remained so for the duration of the study (Fig 2). Effects on diel activity were therefore excluded from the remainder of the study.

Exposure of G. pulexto DBP and DEHP at the 500 µg/L-level resulted in an increasing overall activity during the first day. This increase was probably attributable to drifting since we observed a higher degree of detachment in the initial phase of exposure. Although the system was primarily designed to measure upstream movements, a minor part ofthe total drift was also registered by the photocells. The G. pulex activity peak initially observed for each of the phthalates after exposure to 500 µg/L may have resulted from catastrophic drift. This type of drift is considered tobe an escape reaction in response to a rapid change in water quality. It has previously been used as an indicator to measure water conditions.

The overall locomotor activity of the animals was unaffected by exposure to 100 µg DBP/l ( p< 0.248 for DBP, Fig 4a), with a tendency towards a decreased activity (by approx. 25 -30%) compared with the non-exposed animals. After termination of the exposure activity returned to pre-exposure levels. When exposed to DBP (500 µg/L) the overall locomotor activity of the organism decreased compared with the non-exposed animals (P<0.083, Fig. 4b). This effect also persisted during thepost-exposure period (P<0.083).

Exposure to 500 µg DBP/l led to a decrease in total activity (p< 0.083) which persisted during the post-exposure period (p<0.083). Exposure to 100 µg/l only resulted in a non-significant decrease in aetivity (p<0.248) with a retum to preexposure levels after withdrawal ofthe phthalate.

Conclusions:

The overall locomotor activity of the animals was unaffected by exposure to 100 µg DBP/l ( p< 0.248 for DBP), with a tendency towards a decreased activity (by approx. 25 -30%) compared with the non-exposed animals. After termination of the exposure activity returned to pre-exposure levels. When exposed to DBP (500 µg/L) the overall locomotor activity of the organism decreased compared with the non-exposed animals (P<0.083). This effect also persisted during thepost-exposure period (P<0.083).

Executive summary:

The study investigated in the locomotor activity of G. pulex under phthalate stress. The aim was to determine the effects of DBP and DEHP on overall locomotor activity of G. pulex and the impact of long term exposure on diel activity. Only the effects of DBP are documented here.

Reference 12

Endpoint:

short-term toxicity to aquatic invertebrates

Adequacy of study:

other information

Test organisms (species):

other: G. pseudolimnaeus, Orconectes

Total exposure duration:

96 h

Hardness:

hard water: 272 ppm CaCO3

Test temperature:

21 C

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.1 mg/L

Remarks on result:

other: G. pseudolimnaeus

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 10 mg/L

Remarks on result:

other: Orconectes

Executive summary:

The summarized effects of studies on invertebrates, as stated in the handbook, are documented here.

Reference 13

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Reason / purpose for cross-reference:

reference to same study

Test organisms (species):

other: Moina macrocopa, Dugesia japonica

Remarks on exposure duration:

Moina macrocopa: 3h; Dugesia japonica: 7d

Test temperature:

20 +/-1 °C

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

0.54 mg/L

Nominal / measured:

meas. (geom. mean)

Remarks on result:

other: Dugesia japonica

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

0.84 mg/L

Nominal / measured:

meas. (geom. mean)

Remarks on result:

other: Dugesia japonica

The results obtained are summarized in Table 2. LC50 values for Moina macrocopa were not determined because the number of degree of death did not reach 50% even at saturated concentration.

Conclusions:

No LC50 could be established for Moina macrocopa. The LC50 of Dugesia japonica was 0.84 mg/l and the EC50 was 0.54 mg/l.

Executive summary:

Biological tests using Moina macrocopa (LC50) and Dugesia japonica (EC50 and LC50) were carried out in order to clarify the mutual relationship of test methods.

Description of key information

Measured effect concentrations [mg/l]:
EC50 (48h):    0.76 (Chironomus plumosus) - 5.2 (Daphnia magna)
EC50 (24):     17 (Daphnia magna)
LC50 (96h):     0.8 (Mysidopsis bahia) - 2.1 (Gammarus pseudolimnaeus)
LC50 (24h):     8 (Artemia salina)
EC50 (24h):     10.35 (Daphnia magna)
For the chemical safety assessment the most sensitive endpoints have been chosen:

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.76 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

0.8 mg/L

Additional information

Similar to the testing of DBP on algae also here the determination of effect concentrations is affected by environmental conditions like temperature, humic acid and temperature as this affects the toxicity of DBP. In addition DBP can be enriched and degraded by Scenedesmus obliquus which affects also the toxicity on the test organisms like Daphnia magna.