This week, the ratings of 3 Chemicals stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

E. I. du Pont de Nemours and Company (DD) slips from a C to a D this week. E. I. du Pont de Nemours and Company is a global chemical and life sciences company, with businesses that include agriculture and industrial biotechnology, chemistry, biology, materials science and manufacturing. The company also gets F’s in earnings growth. For more information, get Portfolio Grader’s complete analysis of DD stock.

Slipping from a C to a D rating, Tredegar Corporation (TG) takes a hit this week. Tredegar Corporation manufactures plastic films, elastics and laminate materials, mainly for personal and household care products and packaging and surface protection applications. The company also gets F’s in operating margin growth, earnings growth, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of TG stock.

China Green Agriculture, Inc. (CGA) declines this week from a C to a D. China Green Agriculture, Inc. engages in the research, development, production, and sale of various types of fertilizers and agricultural products in the People’s Republic of China. For more information, get Portfolio Grader’s complete analysis of CGA stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.