The manufacturing economy may not be growing is fast as it did last spring, but it's still expanding, according to PURCHASING magazine's latest Business Survey. After sliding to a barely positive 53.6 in July (50 is considered neutral), PURCHASING's Business Activity Index for chemicals-consuming companies climbed back up to 60 in August. Index tracking chemical buyers' 90-day buying plans continued to edge down in August, but remained near the growth-signaling 60 mark as well. Most supply headaches this month stem from super low stock levels among both manufacturers and distributors. As one chem buyer puts it: "Distributors are panicking because of the economy. They've cut way back on their inventory turns, creating a situation that makes it very difficult to maintain operations." Says another: "Manufacturers and distributors have cut their inventories and increased backorders. [Sometimes] material has to ship from another location." Small-quantity buys are also posing problems. Says one buyer: "Not many manufacturers or distributors handle small pack sizes and those that do are very expensive." Specific chemicals experiencing spot shortages include many types of plastic resins, silicone fluids, beverage grade carbon dioxide gas, acetone and ascorbic acid.