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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information


Phototransformation in air

For 2-isopropylnaphthalene (2-IPN) [CAS No. 2027 -17 -0], a constituent of the substance isopropylnaphthalene (MIPN) [CAS No. 29253-36-9] at approx. 65 %, the half-time of decomposition (DT50%) was 20 to 30 h, when the test material had been coated onto the glass wall of the test tube or adsorbed onto filter paper under artificial UV-test conditions (simulated sunlight).


Due to its chemical structure, isopropylnaphthalene (MIPN) cannot be hydrolysed. The structure of the molecule does not contain any hydrolysable groups.

Phototransformation in water

Using a high-pressure mercury lamp as irradiation source (simulated sunlight), the photolytic half-life of 2-isopropylnaphthalene (2-IPN), was approx. 22 h in distilled water (elimination constant 0.031/h), while it was only approx. 1 h in the presence of salt (0.5 M NaCl).

Phototransformation in soil

No data available (not required for REACH)


Biodegradation in water: screening tests

In a valid follow-up study applying the OECD method 310 (Ready Biodegradability - CO2 in Sealed Vessels, Headspace Test), biodegradation of 60 % was reached after 23 d within a 12-days window, hence just failing the 10-days window (Fiebig/NOACK 2013). GC-analysis demonstrated >99% elimination of the original substance after 16 days. In a MITI II test (OECD 302 B, 28 d) using a concentration of 30 mg/L of MIPN, only poor biodegradation was observed with a low BOD of about 12 %. However, GC-analysis suggested significant primary degradation under test conditions (removal of the pristine test substance of about 93 %). This study has been disregarded, because a negative selective stress usually imposed on the inoculum in these Japanese investigations favour the loss of indigenous potent microorganisms carrying special properties of decomposition.

Biodegradation in water and sediment: simulation tests

No data available

Biodegradation in soil

No data available

Mode of degradation in actual use

No data available (not required for REACH)


Bioaccumulation: aquatic / sediment

In a valid guideline test (OECD 305) [NITE Japan 2011, report date 1982], using flow-through conditions, mean BCF values at steady-state (time 4 to 8 wks) reached 870 and 640 at 50 and 5 µg/L, respectively. Tentative DT50 depuration times can be estimated to be about 1.5 to 2 days. There was no evidence of a high bioaccumulating potential under the standard test conditions applied.

Bioaccumulation: terrestrial

No data available (not required for REACH)

Transport and distribution


Koc for isopropylnaphthalene was estimated to be 7455 using the calculation tool US EPA EPI Suite). Accumulation of MIPN in soil and/or sediment is to be expected.

Henry’s Law constant

Using measured values for vapour pressure and water solubility, Henry's Law constant was determined to be 147 Pa*m³/mol indicating quite rapid volatilisation of MIPN from water into air.

Distribution Modelling

Results of distribution modelling with a Fugacity level III model give evidence that MIPN is distributed mostly into soil (ca. 86%) and to a much lesser degree into water (ca. 9%) and sediment (ca. 4%). Percentage in air is minimal (ca. 0.4%).