This week, the overall grades of four chemicals stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Agrium’s (AGU) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). Agrium is a major retail supplier of agricultural products and services in the Americas, as well as a global producer and marketer of agricultural nutrients and industrial products. In Portfolio Grader’s specific subcategories of Earnings Revisions and Earnings Surprise, AGU also gets F’s. For a full analysis of AGU stock, visit Portfolio Grader.

A. Schulman, Inc.’s (SHLM) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. A. Schulman sells plastic resins and compounds, which are used as raw materials by its customers. The stock’s trailing PE Ratio is 32.60. To get an in-depth look at SHLM, get Portfolio Grader’s complete analysis of SHLM stock.

OM Group, Inc. (OMG) earns a D this week, moving down from last week’s grade of C. OM Group is a global solutions provider of specialty chemicals, advanced materials, and technologies. The stock gets F’s in Cash Flow, Margin Growth and Sales Growth. For more information, get Portfolio Grader’s complete analysis of OMG stock.

Hawkins, Inc. (HWKN) is having a tough week. The company’s rating falls from a D to an F. Hawkins formulates, manufactures, blends, distributes, and sells reagent grade laboratory chemicals and industrial chemicals. To get an in-depth look at HWKN, get Portfolio Grader’s complete analysis of HWKN 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.