Rail-car contamination

Fillers are delivered by traditional means of transportation, including rail cars, road vehicles, ships, and barges. Rail cars are used for delivery of bulk powder, paper sacks, and intermediate bulk containers. Rail cars usually have a capacity between 20 and 55 tons. The car for bulk delivery is compartmentalized usually it has 3 sections, each equipped with release bottom doors, which are usually designed to control the discharge rate. Cars for bulk transportation should be lined with an appropriate coating to avoid contamination of fillers with rust. ... 

A food additive may have screened out of a safety analysis since there are no hazards associated with the product, but the potential for tampering with a loaded tank truck or rail car may raise the concern of potential contamination of the product. Therefore, a review of the measures in place to prevent and detect tampering at the origin, along the route, and at the destination may be warranted. 

Very little information could be identified dealing with -hexane levels in sediments and soils. -Hexane has been identified among the contaminants in an offsite oilfield-disposal pit in New Mexico (Eiceman et al. 1986). Since w-hcxanc is a trace constituent of crude oil and natural gas, as well as a component of refined petroleum products, soil or sediment contamination with -hexane can be expected near oilfield production sites, large soil spills, slush pits and other areas around refineries, and in waste sites where petroleum products or other -hexane-containing wastes had been disposed. Detections would also be likely near many tank storage facilities, pipelines, truck or rail transfer sites, car repair facilities, automobile assembly or storage facilities, and auto and truck fueling facilities (DeLuchi 1993). 

In particle size measurements, one of the most inqKatant problems is the obtaining of a representative sample. It is the most difficult problem, and one that is often overlooked or undoestimated, especially for latexes. This problem increases in magnitude as the sample source increases in size, such that it is easier to obtain a representative sample from a 1-litre container than it is to obtain one from a 200-litre drum and, in turn, it is even more difficult to obtain a representative sample from a rail tank car. The reasons for this are obvious when one takes into consideration such factors as agglomeration, flocculation, settling, contamination and so forth. It is sufficient simply to call attention to this problem while collecting a sample for measurement as well as raising this question before measurements are made. 

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