New 'Store-More' Rectangular Wide Mouth HDPE Jars - complete with caps. Rectangular shape allows a more efficient use of space and permits you to store more chemicals on shelves/cabinets as compared to using standard round containers. We like the idea so much we've started switching all our chemical containers to this new design. Natural color High Density Polyethylene (HDPE). Wide mouth make it easy to dispense contents and reach in with scoops. Same material & specifications as our round HDPE Jars. Container Material Information: HDPE is the most widely used resin for plastic bottles. This material is economical, impact resistant, and provides a good moisture barrier. HDPE is compatible with a wide range of chemicals including acids and caustics but is not compatible with solvents. It is FDA approved for food use. Plastic Bottles made from HDPE are naturally translucent and flexible. While HDPE bottles provide good protection at below freezing temperatures, they cannot be used with products filled at over 160 F or products requiring a hermetic (vacuum) seal. HDPE is NOT suitable for use with essential oils.