It is one of the "Big Five," the five largest kosher certifying agencies in the United States.

In 1935, Abraham Goldstein founded Organized Kashrut Laboratories (OK Labs) to meet the American Jewish community's need for Kosher food products.

Rabbi Levy instituted several improvements in the methods employed by kosher certifying agencies to verify the nature of products.

[3] Upon Rabbi Don Yoel Levy’s death in 2020, the Executive Rabbinical Council took responsibility of the OK.[4] With more than 10 million consumers seeking kosher products in the United States alone, the kosher food industry has seen rapid growth in the past two decades, with sales reaching $165 billion in 2002.

[5] Today the OK Certifies over 140,000 products, produced by over 1500 companies worldwide, including food giants such as Kraft, Snapple, and ConAgra.