2-Ethylhexyl trans-4-methoxycinnamate

Distribution modelling

Administrative data

Endpoint:

distribution modelling

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

December 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scenario specifically developed for UV-filters in sunscreen agents

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

grey literature

Title:

Unnamed

Year:

2001

Materials and methods

Model:

other: Dilution model for a small recreational lake (NL), level III model for large lakes (Switzerland)

Calculation programme:

Model estimations for the release due to the use of sunscreen agents by recreational swimmers to the surface water in various lakes. Surface water and sediment concentrations are estimated using 'level III' multicompartment models.

Release year:

2 001

Media:

other: water, biota, sediment

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexyl 4-methoxycinnamate

EC Number:

226-775-7

EC Name:

2-ethylhexyl 4-methoxycinnamate

Cas Number:

83834-59-7

Molecular formula:

C18H26O3

IUPAC Name:

2-​Propenoic acid, 3-​(4-​methoxyphenyl)​-​, 2-​ethylhexyl ester, (2E)​-

Study design

Environmental properties:

1. NL small pond: diameter 300 meter, depth 2m (to thermocline), contour 1000 meter, surface area 71,000 m^2, water volume 141000 m^3.
2. Swiss lakes dimensions not reported here; they were taken from reference Poiger et al, 2001 and Roche.

Results and discussion

Percent distribution in media

Other distribution results:

Distribution in media:
- NL small pond: 1.5 µg/mL in water
- Swiss lakes:
a. 0.25 - 5 µg/L in water and 0.6 - 2.5 mg/kg in sediment
b. 0.002 - 0.071 µg/L in water and 3 - 15 mg/kg in sediment

Any other information on results incl. tables

1. NL small pond: Total use of sunscreen agents along the shore is 1000 visitors*0.5*3*10 g/day = 15 kg per day. With the assumption that 20 % is released during swimming and 7 % UV-filter content, the surfacewater concentrations becomes:

0.2*15*1000*0.07 kg / 141000 m^3 = 1.5 µg/L.

2. Swiss lakes:

a. With the estimated daily use of 13 g sunscreen agents containing 10 % of UV-filter, an estimated loss to swimming water of 50 % and based on recreational statistics on visitors along the lake, the total emission results in UV-filter concentrations in the surface water ranging from 0.25 to 4 µg/L and sediment concentrations from 0.6 to 2.5 mg/kg (Poiger et al, 2001).

b. Specific for the test substance (in this report called OMC) another assessment was made by Roche based on estimation of waste (10 %), release to natural water during swimming (5 %), 75 % to STP and 25 % in swimming pools. The estimated concentrations range from 0.002 to 0.071 µg/L and sediment levels from 3 to 15 mg/kg.

Applicant's summary and conclusion

Conclusions:

Generic predictions of concentrations of UV filters in surface water suggest that the concentration levels vary from 1.5 µg/L (NL), 0.25 - 4 µg/L or 0.002 - 0.071 µg/L (both in Switzerland). Predicted concentrations in sediment range from 0.6 to 15 mg/kg. The report concludes that these predictions are too high by three orders of magnitude.

Executive summary:

As part of a literature study on the environmental risk of sunscreen agents environmental concentrations of UV-filters were estimated based on well-founded assumptions. One of the ingredients was the test substance, here called OMC. Generic predictions of concentrations of UV filters in surface water suggest that the concentration levels vary from 1.5 µg/L (NL), 0.25 - 4 µg/L or 0.002 - 0.071 µg/L (both in Switzerland). Predicted concentrations in sediment range from 0.6 to 15 mg/kg. The report concludes that these predictions are too high by three orders of magnitude when compared to measured concentrations.