Designed originally as a research tool, SimpleBox4Nano has proven most useful in dedicated environmental fate studies, focused at understanding and predicting environmental fate from fundamental physical and chemical substance properties. Screening-level quantitative model, expresses NP transport and concentrations in and across air, rain, surface waters, soil, and sediment, accounting for nano-specific processes such as aggregation, attachment, and dissolution. The SimpleBox4Nano is a nanomaterial-specific developent of the SimpleBox model, which underpins the EU's chemical risk and safety decision-support tool EUSES. SimpleBox4Nano simulates at regional to continental scale for screening level fate assessment. It can also be used to determine the maximum allowed production volume of NPs in EU since production volume is linear with the predicted milieu concentration.