HollyFrontier to Acquire Sonneborn

Dear valued customer,

As you may already be aware, we were very pleased to share recently that HollyFrontier Corporation
(HFC) has entered into a definitive agreement to acquire Sonneborn.

For more than 100 years, Sonneborn has been setting global industry standards by offering the
finest possible high purity specialty products as one of the world’s largest dedicated suppliers of
white oils, petrolatums and waxes. With manufacturing facilities in North America and Europe,
Sonneborn is the world’s only high purity specialty hydrocarbon producer that offers this global reach
combined with expertise and depth of experience.

The addition of Sonneborn will support HFC’s goal of becoming a leading global supplier of specialty products
through its HollyFrontier Lubricants and Specialty Products division, which includes Petro-Canada Lubricants
and Red Giant Oil. Sonneborn’s brand recognition and diversified portfolio of
products will complement our already strong global business.

The acquisition is subject to customary closing conditions and is anticipated to close in 2019. Until
that time, HFC and Sonneborn remain independent and each company will interact with its
customers, suppliers, distributors and employees separately.

I assure you that quality products and excellent service will remain the highest priority for our
business.

If you have any questions, please reach out to your sales account representative.