Shares of Gujarat State Fertilizers & Chemicals may come under pressure as the company made an emergency shutdown of its ammonia-IV plant on July 6. The shutdown was due to detection of leakage of high-pressure process gas from hot header of reformer box, it said on Monday, and added that the urea-II plant was also shut down due to non-availability of CO2 gas. All other plants of GSFC are operational, GSFC said, but did not say anything about the financial impact of the shutdown.