1,2-Dihydro-2,2,4-trimethylquinoline, oligomers

Endpoint summary

Additional information

Although TMQ is not readily biodegradable and also not inherently biodegradable with nearly no degradation observed up to 35 days, it is abiotically unstable in aquatic environment with a hydrolysis half-life of 16 hours at 23°C and a half-life of direct phototransformation in water of less than 3 minutes. However, these abiotic degradations are of less relevance, since TMQ as a mixture of oligomer derivatives is mostly insoluble TMQ is bioaccumulative with an experimentally determined BCF up to 1300. Simultaneously, TMQ has a high adsorption potential in soil/sludge with the adsorption coefficient (log Koc) mostly above 4.09. TMQ is essentially non-volatile with the estimated Henry's law constant in the range of 2.8*10-9 to 3.0*10-5 Pa*m3/mol at ambient temperature using TMQ-dimer and trimer as typical compositions. The half-life in air of TMQ-dimer and trimer was estimated to be 1.5-2.0 hours which is much shorter than 48 hours and hence no potential for long-range transport of TMQ in air is expected. As a mixture of oligomer derivatives of 1,2-Dihydro-2,2,4-trimethylquinoline with diverse physico-chemical properties, generic distribution is hardly to be modeled. However, considering the low water solubility observed (< 1 mg/l at 20°C), the low vapour pressure (<< 1 Pa), and relatively high Log Pow (5.8 in average) and Log Koc (mostly above 4.09), the TMQ released into environment is expected to be mostly found in sediment and soil compartment.