Reaction mass of 2-(((1-(methacryloyloxy)propan-2-yl)oxy)carbonyl)benzoic acid and 2-((2-(methacryloyloxy)propoxy)carbonyl)benzoic acid

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: YY00GCV000
- Expiration date of the lot/batch: 2017-08-09
- Purity test date: 2017-01-03

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient
- Stability under test conditions: Elevated temperature aging studies (non-GLP) for ZM-120M (unknown lot number)
indicate the active ingredient remains within production specification at 25°C and 37°C
for 200 days (~28 weeks) and at 50°C for 150 days (~21 weeks) (German, 1992).
- Solubility and stability of the test substance in the solvent/vehicle: Expected to be soluble

Analytical monitoring:

yes

Details on sampling:

Samples were collected from the water control and bulk test solution at test initiation and from pooled replicate test vessels at exposure termination. All test solutions were analyzed within 24 hours of preparation; therefore, no stability assessment was required.

Vehicle:

no

Details on test solutions:

An aliquot containing 159 mg methacryloxyisopropyl acid phthalate (adjusted for 62.8% purity) was added to a 1-L volumetric flask, filled to volume with LDW, creating a 100 mg/L bulk test solution. Following direct addition, the bulk test solution was clear
and colorless with undissolved clear droplets on the bottom and throughout the solution. The 100 mg/L bulk test solution was then stirred on a magnetic stir plate utilizing a Teflon lined stir bar at approximately 300 revolutions per minute (RPM) for approximately 24 hours (23 hours actual). Following stirring, the bulk test solution was clear and colorless with white precipitate visible on the surface. The bulk water control consisted of LDW without the addition of the test material. The bulk test solutions were
apportioned into individual test vessels. Individual replicate test solutions were clear and
colorless at test initiation and throughout the exposure period.
The test solutions were utilized on the same day as preparation; thus, assessment of
stability of the test solution was not required. The dispersal of the test material in the
surrounding medium was considered to represent the most probable route of exposure in
the environment.

Test organisms (species):

Daphnia magna

Details on test organisms:

The test organism was the freshwater daphnid, Daphnia magna, from in-house cultures initially obtained from Aquatic BioSystems, Inc. Fort Collins, Colorado. This species is widely accepted and recommended for toxicity testing by the test guidelines. Daphnid neonates less than 24-hours old from a laboratory-reared culture were used as the test organisms. Neonates were only used from daphnids which have had at least 3 broods. The day before neonates were needed for testing (< 24 hours prior to test initiation), adults within the culture vessels were removed and transferred to new culture vessels. On the following day, neonates produced overnight in these culture vessels were removed and placed into a glass beaker containing LDW. These neonates (< 24 hours old) were held in an incubator until used for the study.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No post exposure period.

Hardness:

66 mg CaCO3/L

Test temperature:

19-20°C

pH:

6.5-7.9

Dissolved oxygen:

7.5–8.6 mg/L (84–97% air saturation)

Salinity:

Not applicable

Conductivity:

168 μS/cm

Nominal and measured concentrations:

Nominal: 0 (water control) and 100 mg methacryloxyisopropyl acid phthalate/L
Measured:

Details on test conditions:

TEST SYSTEM
The test vessels were 50-mL beakers each containing approximately 40 mL of control or test solution and covered to reduce evaporation. Each test vessel was uniquely labeled for identification purposes (i.e., replicate, study, test level).
The definitive test was conducted as a limit test under static conditions for approximately 48 hours from 11 to 13 July 2017. Four replicate test vessels, each containing approximately 40 mL of the appropriate test solution, were prepared for the 100 mg/L
limit test level and water control. Twenty daphnids (five daphnids per replicate) were impartially added to each test level within 30 minutes of completion of test solution preparations. The target test temperature was 20 ± 2°C, not to vary by ± 1ºC over the
course of the exposure. The photoperiod was set at 16 hours light/8 hours dark per day. Daphnids were not fed during the test. Daphnids were observed for immobility (inability to swim within approximately 15 seconds after gentle agitation of the test vessel) at approximately 24 and 48 hours of exposure (± 1 hour from test initiation). Any sublethal effects observed (abnormal behavior or appearance) were recorded. Dissolved oxygen, pH, and temperature data were recorded from the bulk test solutions at test initiation and from all replicate test vessels (spent test solutions) at exposure termination. Water temperature was continuously monitored with a minimum/maximum thermometer placed in a surrogate vessel containing LDW located in the test area. Light intensity was measured at test initiation. Water hardness, alkalinity, and conductivity were measured from the bulk test solutions at test initiation.

TEST MEDIUM / WATER PARAMETERS
The water used for daphnid testing and culturing (referred to as laboratory dilution water or LDW) was Lake Huron water supplied to The Dow Chemical Company (TERC Laboratory) by the City of Midland Water Treatment Plant. The water was obtained from the upper Saginaw Bay of Lake Huron off Whitestone Point and was limed and flocculated with ferric chloride. Before use in the laboratory, the water was sand-filtered, pH-adjusted with gaseous CO2, carbon-filtered, and UV-irradiated.
The water is typically monitored weekly for pH, alkalinity, hardness and conductivity. Periodically, the water is monitored for total organic carbon (TOC), total suspended solids (TSS), and selected inorganic and organic compounds. Results from the most
recent analysis of the dilution water indicated that TOC was 1.7 mg/L, TSS was < 2 mg/L, and concentrations of contaminants were below levels of concern that may have interfered with the results of this test.



VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
A non-GLP 48-hour range-finding test was conducted from 20 to 22 June 2017. Two replicates of five daphnids per test level were exposed to nominal test concentrations of 0 (water control), 1, 10 and 100 mg methacryloxyisopropyl acid phthalate/L (adjusted for 62.8% purity), over a 48-hour static exposure period. An aliquot containing 159 mg methacryloxyisopropyl acid phthalate was added to a 1-L volumetric flask, filled to volume with LDW, creating a 100 mg/L bulk test soluton. Following direct addition, the bulk test solution was clear and colorless with undissolved clear droplets on the bottom and throughout the solution. The 100 mg/L bulk test solution was then stirred on a magnetic stir plate utilizing a Teflon lined stir bar at approximately 300 revolutions per minute (RPM) for approximately 24 hours. Following stirring, the bulk test solution was clear and colorless with no apparent undissolved test material visible. The remaining bulk test solutions were prepared as dilutions of the 100 mg/L bulk test solution. The prepared bulk test solutions were apportioned into individual test vessels. The water control consisted of LDW without the addition of the test material. All test solutions, including the water control, were clear and colorless at
test initiation and throughout the exposure period. Observations for daphnid immobility and sublethal effects were made at approximately 24 and 48 hours after test initiation (± 1 hour from exposure initiation). Water quality (i.e., pH, temperature, DO, alkalinity, hardness, conductivity) measurements were within guideline specified ranges during the test. Following 48 hours of exposure, no immobility or sublethal effects were observed in any of the test levels, including the water control.
Based on information from the range-finding test, a single nominal exposure concentration of 100 mg methacryloxyisopropyl acid phthalate/L (adjusted for 62.8% purity), was selected for the definitive study (limit test). LDW, without the addition of
test material, served as the water control.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobility or sublethal effects (change in daphnid behavior or appearance) were observed in the water control or the 100 mg methacryloxyisopropyl acid phthalate/L test level over the course of the exposure.

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity values for Daphnia magna exposed to methacryloxyisopropyl acid phthalate, over a 48-hour static exposure period and based on nominal concentrations, were as follows:
• 24- and 48-hour EC50 values: >100 mg/L (limit concentration tested)
• The 48-hour NOEC: 100 mg/L (limit concentration tested)

Executive summary:

The purpose of this study was to assess the potential effects of methacryloxyisopropyl acid phthalate to the freshwater cladoceran, Daphnia magna. The study was conducted as a limit test with four replicate vessels of five daphnids per test level, exposed to nominal test concentrations of 0 (water control) and 100 mg methacryloxyisopropyl/L, over a 48-hour static exposure period. Observations were made at 24 and 48 hours (±1 hour from exposure initiation) for daphnid immobility (inability to swim within approximately 15 seconds after gentle agitation of the test container) and any changes in behavior or appearance.

Temperatures during the exposure period ranged from 19-20°C. Dissolved oxygen levels ranged from 7.5-8.6 mg/L (84-97% air saturation). The pH ranged from 6.5-7.9 and the light intensity ranged from 301-312 lux. Test solutions were analyzed for methacryloxyisopropyl acid phthalate concentrations at test initiation and exposure termination by high performance liquid chromatography/mass spectrometry (HPLC/MS-MS). None of the analyses of the water control exhibited a concentration exceeding the lower limit of quantitation (LLQ) equivalent to 0.250 mg methacryloxyisopropyl acid phthalate/L. Measured concentrations of methacryloxyisopropyl acid phthalate ranged from 92.2 to 95.0% of the nominal concentration over the course of the exposure period. The resulting mean measured concentration was 93.6 mg

methacryloxyisopropyl acid phthalate/L, equating to 93.6% of the nominal concentration. Because the mean measured concentration was within ± 20% of the nominal target concentration, results were based on the nominal (limit) concentration. The acute toxicity values for daphnid (D. magna) exposed to methacryloxyisopropyl acid phthalate over a 48-hour exposure period and based on nominal concentrations were as

follows:

• 24- and 48-hour EC50 : >100 mg/L (limit concentration tested)

• 48-hour NOEC: 100 mg/L (limit concentration tested)

Description of key information

In an acute, static, toxicity study with Daphnia magna,the 48-hour EC50 value for methacryloxyisopropyl acid phthalate was >100 mg/L based on nominal concentrations. The 95% confidence interval based on nominal concentrations was not determined. Measured concentrations of methacryloxyisopropyl acid phthalate ranged from 92.2 to 95.0% of the nominal concentration over the course of the exposure period.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

One static acute toxicity test withDaphnia magnawas available for methacryloxyisopropyl acid phthalate. This study was assigned a Klimisch score of 1. The 48-hour EC50 value (based on immobility) was reported as >100 mg methacryloxyisopropyl acid phthalate /L. This value was based on initial nominal concentrations. Thus, the key parameter for the acute invertebrate endpoint was the EC50 value of >100 mg/L.