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Phthalate Di-isodecyl & Di-isononyl phthalates

3. Can DIDP and DINP affect the environment?

  • 3.1 What happens to DIDP and DINP released into the environment?
  • 3.2 When are DIDP and DINP released?
  • 3.3 What levels of DIDP and DINP are expected near the sources?
  • 3.4 What are the possible effects of DIDP and DINP on the environment?
  • 3.5 What are the risks of DIDP and DINP to the environment?

The source document for this Digest states:

DIDP

ENVIRONMENTAL EXPOSURE

As DIDP is an isomeric mixture, the fate and behaviour of the substance cannot be determined with accuracy. Each component of the mixture would tend to have different characteristics concerning its fate and behaviour in the environment. Nevertheless, an overall picture can be drawn, as presented below.

Source & ©: ECB "2003 Risk Assessment Report (RAR 041) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

DINP

ENVIRONMENTAL EXPOSURE

As DINP is an isomeric mixture, the fate and behaviour of the substance cannot be determined with accuracy. Each component of the mixture would tend to have different characteristics concerning its fate and behaviour in the environment. Nevertheless, an overall picture can be drawn, as presented below.

Source & ©: ECB "2003 Risk Assessment Report (RAR 046) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

For more information, see the full ECB Risk Assessment Report:
 Chapter 3: Environment

The same information on
DBPDEHP

3.1 What happens to DIDP and DINP released into the environment?

The source document for this Digest states:

DIDP

The major characteristics of DIDP relevant for the exposure assessment are:

  • no hydrolysis in water,
  • readily degradable but failing the 10-day window criterion; (based on results from simulation tests performed with diethylhexyl phthalate (DEHP), representative half-lives in surface water, soil and sediment of respectively 50, 300 and 3,000 days could be estimated for DIDP),
  • an estimated atmospheric half-life of 0.6 day.

The high log Kow values imply a high potential for bioaccumulation, strong sorption to sewage sludge, soils and sediments and very low mobility in soil (Koc values of 111,000-611,000 l/kg). Bioconcentration factors (whole body values ranging from &14.4 to 4,000) have been reported with certain freshwater organisms.

Based on the model SIMPLETREAT, it is estimated that in sewage treatment plants, 84.8% of any discharged DIDP will be adsorbed on to sludge, 3.9% will be degraded and 3.2% will be stripped to air, with the remaining 8.1% being released with the aqueous effluent.

Source & ©: ECB "2003 Risk Assessment Report (RAR 041) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

DINP

The major characteristics of DINP relevant for the exposure assessment are:

  • no hydrolysis in water,
  • readily degradable;(based on results from simulation tests performed with diethylhexyl phthalate (DEHP), representative half-lives in surface water, soil and sediment of respectively 50, 300 and 3,000 days could be estimated for DINP),
  • an estimated atmospheric half-life of 0.7 day.

The high log Kow values imply a high potential for bioaccumulation, strong sorption to sewage sludge, soils and sediments and very low mobility in soil (Koc values of 111,000- 611,000 l/kg). Bioconcentration factors (whole body values ranging from 800 to 4,000) have been reported with certain freshwater organisms.

Based on the model SIMPLETREAT, it is estimated that in sewage treatment plants, 82% of any discharged DINP will be adsorbed on to sludge, 10% will be degraded and 1% will be stripped to air, with the remaining 7% being released with the aqueous effluent.

Source & ©: ECB "2003 Risk Assessment Report (RAR 046) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

For more information, see the full ECB Risk Assessment Report:
 Chapter 3: Environment

The same information on
DBPDEHP

3.2 When are DIDP and DINP released?

The source document for this Digest states:

DIDP

Environmental releases

Releases from production have been estimated from site-specific information. Industry information has also been used to estimate emissions from the manufacture of polymeric material. No specific information was found for the use of DIDP paints, sealing compounds and textile inks, and so default release factors from the EU Technical Guidance Document (TGD) were used.

Furthermore, the releases from polymeric articles during their use as well as during their disposal were estimated in a very preliminary manner. The overall releases are shown in Table 3.1

Table 3.1 Total releases to waste water, surface water and air (DIDP)

Source & ©: ECB "2003 Risk Assessment Report (RAR 041) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

DINP

Environmental releases

Releases from production have been estimated from site-specific information. Industry information has also been used to estimate emissions from the manufacture of polymeric material. No specific information was found for the use of DINP in inks, adhesives, sealants, paints and lacquers, and so default release factors from the EU Technical Guidance Document (TGD) were used.

Furthermore, the releases from polymeric articles during their use as well as during their disposal were estimated in a very preliminary manner. The overall releases are shown in Table 3.1

Table 3. 2 PECs calculated for the various stages of the life cycle of DIDP

Source & ©: "Environmental Health Criteria for Fluorides", EHC 227, 
ECB "2003 Risk Assessment Report (RAR 046) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

For more information, see the full ECB Risk Assessment Report:
 Chapter 3: Environment

The same information on
DBPDEHP

3.3 What levels of DIDP and DINP are expected near the sources?

The source document for this Digest states:

DIDP

Environmental concentrations

The methods in the TGD were used to estimate Predicted Environmental Concentrations (PECs) for water, sediment, sewage treatment plants, air, soil and biota. Table 3.2 shows the PECs calculated for the various stages of the life cycle of DIDP, including regional concentrations in the different environmental compartments. The calculated levels in air are very low for all life-cycle stages and so are not represented here. The majority of the PECs are consistent with measured data.

Table 3. 2 PECs calculated for the various stages of the life cycle of DIDP

Source & ©: ECB "2003 Risk Assessment Report (RAR 041) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

DINP

Environmental concentrations

The methods in the TGD were used to estimate Predicted Environmental Concentrations (PECs) for water, sediment, sewage treatment plants, air, soil and biota. Table 3.2 shows the PECs calculated for the various stages of the life cycle of DINP, including regional concentrations in the different environmental compartments. The calculated levels in air are very low for all life-cycle stages and so are not represented here. The majority of the PECs are consistent with measured data.

Table 3.2 PECs calculated for the various stages of the life cycle of DINP

Source & ©: ECB "2003 Risk Assessment Report (RAR 046) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

For more information, see the full ECB Risk Assessment Report:
 Chapter 3: Environment

The same information on
DBPDEHP

3.4 What are the possible effects of DIDP and DINP on the environment?

The source document for this Digest states:

DIDP

EFFECTS ASSESSMENT

Aquatic compartment

Acute toxicity tests have been performed with several fish and invertebrate species. No effects were seen at the concentrations up to and above the solubility limit of the substance. No long-term test results with fish exposed via the water phase are available, but a two-generation feeding study has been carried out with Oryzias latipes, in which no impact on any populational parameter was observed. Apart from physical effects (e.g. entrapment), no effects were seen in reproduction studies with Daphnia magna. Furthermore, no impact on the growth of algae was observed in several species up to and beyond the solubility limit of DIDP.

Similarly, no inhibition of the respiration of activated sludge was observed.

Several laboratory assays were performed on sediment dwellers, showing no effects up to the highest tested concentrations (3,000 – 10,000 mg/kg dw). Furthermore, the hatching and development of frog eggs in contact with sediment containing DIDP up to concentrations of 600 mg/kg dw was not affected. As it could be concluded that DIDP does not have adverse effects towards aquatic or benthic organisms at the limit of water solubility in laboratory tests, no PNECs could be derived.

Potential for endocrine disruption

The most relevant test result is from the multigeneration study with Oryzias latipes. There were no statistically significant changes in mortality or fecundity between the treatment groups. There was no reduced egg production. Evaluation of F1 and F2 embryos showed normal development. The male to female ratios (3:1) in all groups were similar. Phenotypic gender classification of male and female fish was histopathologically confirmed to be 100% correct. Ale somatic gonadal index and liver somatic index were not significantly different in any group. Based on these data there does not appear to be an impact on any populational parameter from chronic exposure to DIDP on fish.

Atmosphere

Some phthalates, especially dibutylphthalate (DBP) have shown to be toxic to plants via the atmosphere. Experiments performed with DEHP and DIDP did not reveal any effects upon plants, but due to experimental shortcomings they do not allow to conclude an absence of toxicity of DIDP to plants via the gas phase. No PNEC can be determined.

Terrestrial compartment

Short-term tests were performed with plants and earthworms. No effects were observed up to a concentration of 10,000 mg/kg dw. An assessment factor of 100 is applied instead of 1,000 as no LOECs could be determined, resulting in a PNECsoil of 100,000 µg/kg dw.

Secondary poisoning

The lowest overall NOAEL of 15 mg/kg bw/d has been determined in a 13-week repeated dose study with dogs. This corresponded to a food concentration of 500 mg/kg. Using an assessment factor of 10, a PNECoral of 50 mg/kg can be estimated for top predators.

Source & ©: ECB "2003 Risk Assessment Report (RAR 041) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

DINP

EFFECTS ASSESSMENT

Aquatic compartment (including microorganisms and benthic organisms)

Acute toxicity tests have been performed with several fish and invertebrate species. No effects were seen at the concentrations up to and above the solubility limit of the substance. Available long-term test results with fish exposed via the water phase were considered to be invalid. Furthermore, a two-generation feeding study has been carried out with Oryzias latipes, in which no impact on any populational parameter was observed. Apart from physical effects (e.g. entrapment), no effects were seen in reproduction studies with Daphnia magna. Furthermore, no impact on the growth of algae was observed in several species up to and beyond the solubility limit of DINP.

Similarly, no inhibition of the respiration of activated sludge was observed.

Several laboratory assays were performed on sediment dwellers, showing no effects up to the highest tested concentrations (3,000 – 10,000 mg/kg dw). Furthermore, the hatching and development of frog eggs in contact with sediment containing DINP up to concentrations of 1,000 mg/kg dw was not affected. As it could be concluded that DINP does not have adverse effects towards aquatic or benthic organisms at the limit of water solubility in laboratory tests, no PNECs could be derived.

Potential for endocrine disruption

The most relevant test result is from the multigeneration study with Oryzias latipes. There were no statistically significant changes in mortality or fecundity between the treatment groups. There was no reduced egg production. Evaluation of F1 and F2 embryos showed normal development. The male to female ratios (3:1) in all groups were similar. Phenotypic gender classification of male and female fish was histopathologically confirmed to be 100% correct. Ale somatic gonadal index and liver somatic index were not significantly different in any group. Based on these data there does not appear to be an impact on any populational parameter from chronic exposure to DINP on fish.

Atmosphere

Some phthalates, especially dibutylphthalate (DBP) have shown to be toxic to plants via the atmosphere. No results are available with DINP. Experiments performed with DEHP and DIDP did not reveal any effects upon plants, but due to experimental shortcomings they do not allow to conclude an absence of toxicity of DINP to plants via the gas phase. No PNEC can be determined.

Terrestrial compartment

Short-term tests were performed with plants and earthworms. Long-term test results are available with plants and microorganisms. A result regarding inhibition of germination in a short-term test was not confirmed in a corresponding long-term test. The highest tested concentrations range from 1,500 to 10,000 mg/kg dw. The NOEC of 1,500 mg/kg will therefore be used with an assessment factor of 50 resulting in a PNEC of 30,000 µg/kg dw.

Secondary poisoning

The lowest overall NOAEL of 88 mg/kg bw/d has been determined in a two-year repeated dose study with rats. This corresponded to a food concentration of 1,500 mg/kg. Using an assessment factor of 10, a PNECoral of 150 mg/kg can be estimated for top predators.

Source & ©: ECB "2003 Risk Assessment Report (RAR 046) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

For more information, see the full ECB Risk Assessment Report:
 Chapter 3: Environment

The same information on
DBPDEHP

3.5 What are the risks of DIDP and DINP to the environment?

The source document for this Digest states:

DIDP

RISK CHARACTERISATION

Aquatic compartment (including sediment and waste water treatment plants)

The highest value estimated for a STP outlet is 20.75 mg/l. No PNEC could be derived, as no effects at the limit of water solubility could be observed. Conclusion (ii).

No chemical toxic effects of DIDP towards fish, invertebrates or algae could be observed in any of the performed long-term tests. No NOECs could be derived. The assessment scheme proposed in the TGD can therefore not be used to derive a PNEC for the aquatic compartment. As furthermore, a two-generation study in fish exposed orally was performed, showing no impact on any populational parameter, it can tentatively be concluded that DIDP does not cause adverse chemical effects towards the aquatic ecosystem. Conclusion (ii). Regarding the benthic compartment, long-term tests have been performed with vertebrates (moorfrog) and invertebrates (midge). No effects could be observed in any of the tests. No NOECs could be derived. It can therefore tentatively be concluded, that this compound does not cause adverse effects towards benthic organisms. Conclusion (ii).

Atmosphere

It is so far not possible to realise a biotic assessment in the same way as described for other compartments. No PNEC could be derived from the results available, as no dose-response relationship could be established. The absence of adverse effects in the test systems does not give rise for immediate concern though. Conclusion (ii).

Terrestrial compartment

In Table 3.3, the ratios PEC/PECsoil are shown. Local PECsoil for production sites have not been calculated as most producers dispose of their sewage sludge either through incineration or landfilling.

Table 3.3 PEC/PEC ratios for agricultural soil

As all calculated PEC/PNEC ratios are below 1, it can be concluded that there is no risk to soil dwelling organisms through DIDP. Conclusion (ii).

Secondary poisoning

In Table 3.4, the PEC/PNEC ratios for top predators are presented.

Table 3.4 PEC/PNEC ratios for predators

As all PEC/PNEC ratios are below 1, it can be concluded that there is no risk towards top predators from DINP. Conclusion (ii).

Source & ©: ECB "2003 Risk Assessment Report (RAR 041) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

DINP

RISK CHARACTERISATION

Aquatic compartment (including sediment and waste water treatment plants)

The highest value estimated for a STP outlet is 3.4 mg/l. No PNEC could be derived as no effects at the limit of water solubility could be observed. Conclusion (ii).

No chemical toxic effects of DINP towards fish, invertebrates or algae could be observed in any of the performed long-term tests. No NOECs could be derived. The assessment scheme proposed in the TGD can therefore not be used to derive a PNEC for the aquatic compartment. As furthermore, a two-generation study in fish exposed orally was performed, showing no impact on any populational parameter, it can tentatively be concluded that DINP does not cause adverse chemical effects towards the aquatic ecosystem. Conclusion (ii). Regarding the benthic compartment, a long-term test has been performed with vertebrates (moorfrog) and a read-across from long-term tests performed with DEHP and DIDP on invertebrates (midge) can be performed. In none of the test systems could any effects be observed. No NOECs could be derived. The equilibrium partitioning model described in the TGD cannot be used to estimate a PNECsediment as no aquatic PNEC could be derived due to the lack of identified adverse effects. It can therefore tentatively be concluded, that this compound has no adverse effects towards benthic organisms. Conclusion (ii).

Atmosphere

It is so far not possible to realise a biotic assessment in the same way as described for other compartments. No results are available with DINP. No PNEC could be derived from the results available for analogues e.g. DIDP, as no dose-response relationship could be established. The absence of adverse effects in the test systems does not give rise for immediate concern though. Conclusion (ii).

Terrestrial compartment

In Table 3.3, the ratios PEC/PNECsoil are shown. Local PECssoil for production sites have not been calculated as most producers dispose of their sewage sludge either through incineration or landfilling.

Table 3.3 PEC/PNEC ratios for agricultural soil

As all calculated PEC/PNEC ratios are below 1, it can be concluded that there is no risk to terrestrial organisms through DINP. Conclusion (ii).

Secondary poisoning

In Table 3.4, the PEC/PNEC ratios for top predators are presented.

Table 3.4 PEC/PNEC ratios for predators

As all PEC/PNEC ratios are below 1, it can be concluded that there is no risk towards top predators from DINP. Conclusion (ii).

Source & ©:   "2003 Risk Assessment Report (RAR 046) on
Di-"isodecyl" Phthalate (DIDP), Summary of the Report, chapter 3: Environment

For more information, see the full ECB Risk Assessment Report:
 Chapter 3: Environment

The same information on
DBPDEHP

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