The Occupational Safety and Health Administration says serious health problems among workers required to do repetitive physical labor on assembly lines prompted the agency's second-largest fine ever against a single company.

IBP Inc. says OSHA is trying to impose "Alice in Wonderland theories" on industry, but the union representing workers at IBP's Dakota City, Neb., meatpacking plant hailed Wednesday's decision to get tough with the company.OSHA said it was imposing a $3.1 million fine against IBP for willfully ignoring the hazards of repetitive motion. The agency maintains that IBP could have taken numerous steps to reduce the risk of injury but did not.

The affected employees work on production lines, doing such work as cutting, trimming, hide removal and lifting meat with hooks, said OSHA spokesman Terry Mikelson. All the work is done while the meat moves at high speed through work stations in a cold, damp environment.

Mikelson said safety inspectors from the agency first "noticed a pattern of repetitive motion injuries" during a preliminary review of safety records in November 1987. Such injuries can be crippling and are caused by repeated hand, wrist and arm motion.

OSHA Deputy Assistant Secretary Frank White said repetitive motion injuries are "a major health hazard in one of the most dangerous occupations in the country, and we want the meatpacking industry, in general, and IBP, in particular, to eliminate the problem."

OSHA says IBP refused to slow production lines, redesign equipment or educate workers on the need to change positions periodically.