Inventory Representation For Products

C.F.R. 710.4(c)(2) see also Toxic Substances Control Act Inventory Representation For Products Containing Two Or More Substances Formulated And Statutory Mixtures (undated) [hereinafter Formulated and Statutory Mixtures] available at http //regulations. gov in docket number EPA-HQ-OPPT-2007-0392. 

Toxic Substances Control Act Inventory Representation For Products Containing Two Or More Substances Formulated And Statutory... 

See, e.g.. Toxic Substances Control Act Inventory Representation for Combinations of Two or More Substances Complex Reaction Products, available at http //www.epa.gov/oppt/ newchems/pubs/rxnprods.txt. 

UVCB substances are substances of unknown or variable composition, complex reaction products, and biological materials that cannot be represented by unique structures and molecular formulas. Some UVCB substances are not adequately described by their CA Names and have supplemental definitions that are considered integral parts of the names for TSCA purposes. The guidance, entitled Toxic Substances Control Act Inventory Representation For Chemical Substances Of Unknown Or Variable Composition, Complex Reaction Products And Biological Materials UVCB Substances points out that any substance that matches a CA Name but is not covered by the substance description is not considered to be covered by that Inventory listing. 

The guidance on how to name complex reaction products is entitled Toxic Substances Control Act Inventory Representation for Combinations of Two or More Substances Complex Reaction Products. It applies only to chemicals made by a chemical reaction, and not to formulated mixtures, which are made simply by mixing with no chemical reaction. Its primary purpose is to explain when complex reaction products should be named as one reaction product, or as a series of individual components. 

Toxic Substances Control Act Inventory Representation For Chemical Substances Of Unknown or Variable Composition, Complex Reaction Products And Biological Materials UVCB Substances, available through http //www.epa.gov/opptintr/newchems/pubs/guideman.htm... 

Thanks to the differentiated representation, individual changes can be shown in greater detail. A permanent reduction of the inventories of raw, auxiliary and operating materials (q=l) in the goods-in warehouse (p=2) would correspond to some 10% for product group I of the formula ojf=(0.1 0 0). 

The major challenge in the model formulation is the representation strategy adopted for the tank cycle. Normal operation considers that each tank is filled up completely before settling. After the settling period, the tank is released for clients satisfaction, until it is totally empty. These procedures are usually related to the product quality, where it isn t desired to mix products from several different batches. This implies that they are formulated four states for each tank i) full, ii) delivering product to clients, iii) empty and iv) being filled up with product from the pipeline. Each one of the states has a corresponding state variable, related to tank inventory ID), and has to be activated or deactivated whenever a boundary situation occurs (Eq. 1) the maximum UB) and minimum LB) capacities of the tank are met. For this purpose, the state variable y, binary) will have to be activated whenever both inequalities ( < and > ) hold (Eq. 2) ... 

This basic picture of organic aerosol was relatively well developed by the end of the 1990s. Chemical transport models were fed by inventories for POA emissions from a wide array of sources, and those emissions were treated in a variety of microphysics modules as effectively non-volatile and often chemically inert particles [19, 20]. SOA models evolved from relatively primitive treatments that simply converted a fixed fraction of VOC emissions into equally non-volatile secondary material (for example 12% of monoterpene emissions) to more sophisticated two-product representations that treated the equilibrium partitioning of surrogate species based on smog-chamber experiments [21-23]. Even today some global-scale models represent SOA as a fixed non-volatile fraction of VOC emissions [24, 25]. 

Figure 22.2 Schematic representation of an inpnt/ontput inventory for the life-cycle assessment of a product.

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