Product-relevant physicochemical parameters

Plasticizers are key additives in many plastics and are therefore important constituents of a variety of products - not only electrical insulation, wall coverings, lubricants and floor carpets but also such items as food packaging, bottled water containers, toys, cosmetics and medical materials. Due to the high volume of the production of phthalates many reviews focus on their implications on human exposure and public health. We will discuss here the properties of some other representative plasticizers besides phthalic esters. Some of their relevant physicochemical parameters are collected in Table 3. 

The behavior of MTBE through the different environmental compartments has been investigated using various modelling approaches. For example, the EU risk assessment used the simplest type of fugacity models (a Level 1 model) and concluded that from diffuse sources 93.9% of MTBE is in the air phase, 6.0% in the water phase, and 0.05% in the soil phase [2]. However, another study by Environment Canada for Southern Ontario [61] used the Level III model and predicted 56% of MTBE in the air, 42% in surface water, and 0.5% in soil and sediment. As can be observed, models developed so far differed in their predictions of relative MTBE concentrations for relevant environmental compartments and of seasonal concentration variations further, they have hardly considered the formation of transformation products [62]. Moreover, limitations in pollutant environmental data or key physicochemical parameters often make it difficult to validate model predictions. 

Purity requirements depend on the intended use of the biopharmaceutical, dose and risk-benefit ratio. The selection of purification method should consider physicochemical characteristics of the particle to be isolated. For viral particles it is relevant to consider the influence of isoelectric point (pi), surface hydrophobicity, the presence or absence of an envelope, hydrodynamic diameter and lability of virus particles. Viruses should not have their level of infectivity reduced after a purification stage when they are used as vectors, and tests should be carried out to check this. ° During the process of vaccine manufacturing, the production of virus-like particles is dependent on physicochemical parameters such as pH, ionic strength and medium temperature. Type and concentration of chelating agents also seem to affect the protein macrostructure stability and thus should be observed. ... 

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