My comments on recession come strictly from news and from petrochemical industry publications. I have not seen any indication that manufacturing of specialty chemicals (at least in the waters I swim in) are as yet affected by the economic turmoil that the lending fiasco triggered. Eventually orders will taper some, but the how much and when is not at all clear.
It takes a while for the effects of a downturn to filter upstream to all sectors of chemical manufacturing. The first effects will likely be a pushback on delivery of existing orders. Then, the period between succesive orders will lengthen as businesses closer to the consumers will start to trim down inventories and throughput. Finally, sales forecasts will begin to report spotty sales projections 2 or 3 quarters out. Eventually, you run into those weak quarters and have to find a way to limp through them.
The important question relating to petrochemicals (aromatics, naphtha, ethylene, propylene, etc) is where does price elasticity really kick in for hydrocarbon intensive goods as crude prices continue to rise and the dollar continues to devalue?
Packaging materials like PE, PS, and PP, etc. are very often not the primary product consumers are looking for. They are produced for sellers of consumer goods as packaging materials. The purchasing decision maker is not the person strolling down the isles of Wal-Mart, but rather the product manufacturers who have to package the goods.
This economic disturbance seems unique. Demand from the global middle class is growing as the US economy falters. Demand for hydrocarbon fuels and manufacturing feedstocks is strong from Asia for their own consumption. But Asian production is also strongly linked to the demand of their products from the west. Predicting how this thing plays out is very tricky.
Polymer membranes, HDPE pipe, PVC pipe, automotive assemblies and fascia are all large consumers of hydrocarbon products. Demand for these materials, obviously, should parallel the health of construction and automotive industries. But as the US transitions to a net importer of polymers, the connection to US economics is murky.
I suppose the best business to be in is war profiteering and security, at least as long as a war president is in office. It seems to be shielded from the raw forces of economics. As long as the gov’t can print money, special interests can be paid. A good career would be as a translator between Arabic and Mandarin.
Lamentations on Chemistry 
How far out are orders on petrochemical products (i.e. napthalene) placed? 1 qt or one year? Can they be easily canceled or does the buyer take a hit (generally).
It seems like global population growth, and a general increase in global per capita GDP means the baseline level of consumption of these petrochemical products will continue to rise and thus offset short term economic depression. You have declining sources and rising baseline demand. Political instability in ASIA is the only thing that could derail this train.
Commodity hydrocarbons are best bought and sold on contract. Spot orders offer the poorest pricing, long term agreements offer the best pricing. I have never been involved in anything bigger than single tank truck scale, so I can’t speak from experience. There is often an escape clause of some sort in these contracts, though not automatically.
The rise of the global middle class will accelerate the depletion of easy raw materials in the next few decades. Americans should travel to europe or japan to see what a lower consumption life is like.