Oct. 9, 2023 It's important to use the correct funnel for your waste container and take steps to prevent overpressurization. Safety funnels are devices that are designed to be attached to a waste container to facilitate addition of waste to the container. When adding waste, the wider funnel body makes waste addition easier and minimizes risk of spillage. When not adding waste, the funnel lid should be securely closed. The funnel lid contains a gasket, so that when the lid is fully closed, the waste container is fully closed so that volatile waste fumes cannot escape. Tip 1: Use plastic waste containers instead of glass EHS provides several sizes of plastic (HDPE) waste containers through the EHS safety supply store to help eliminate glass waste containers that are more likely to fail catastrophically if accidentally struck or if over-pressurization occurs. If your waste is not compatible with the HDPE waste containers, then you should not use a safety funnel as the waste will likely degrade the funnel, also made of HDPE. Safety funnel manufacturers recommend against glass collection containers as over-tightening on the glass threads can lead to separation/splitting of the safety funnel’s threaded adapter from the funnel body. Below is a list of HDPE waste containers currently offered through the EHS Safety Supply Store correlated to the applicable safety funnel adaptor threading. Adapter Size Compatible Plastic Waste Containers on EHS Safety Supply Store 38-430mm 1 gal HDPE Utility Jug (Uline S10746) 63B 1 gal HDPE EZ-Pour Jug (Uline S20045) 70mm (Rieke 6TPI) 5 gal HDPE Carboy Tip 2: Protect against safety funnel over-pressurization Like any closed container, a closed safety funnel can build pressure if incompatible wastes are added that lead to gas evolution or rapid heating. In combination with a glass waste container, the result of an over-pressurized safety funnel can be disastrous. Figure 2 Result of a glass waste container over-pressurizing with closed Safety Funnel Be mindful of the waste being added to a waste container to avoid combining incompatible waste. After adding waste, continue to monitor for trouble signs: gas evolution/bubble formation heat generation phase separation If trouble signs are observed, do not close or leave the waste container unattended until issue(s) have been addressed. Consider a safety funnel with a side-vent option. Many safety funnels offer a side vent option when they are used in conjunction with liquid handling systems (like HPLCs). The side vent can use used to attach a vent filter that minimizes evaporative loss while still providing some pressure relief capability. Figure 3 Safety Funnel with side vent. Image provided by CPLabSafety, www.calpaclab.com. On the vent filter’s outlet, consider attaching a balloon which can provide an effective visual indicator of when the waste container is under pressure (balloon inflates). Tip 3: Keep waste streams organized and identifiable Safety funnels are often available with options for the lid color. Use either the color lids or other forms of labeling to help differentiate different waste streams associated with the safety funnels. Figure 4 Safety funnel lid color options. Image provided by CPLabSafety, www.calpaclab.com Additionally, labels on the lid of the funnel and body of the funnel can be used to effectively identify waste streams and reduce the risk of mixing incompatible waste streams. Tip 4: Prevent waste container tipping When a new waste container is started, the additional mass of the safety funnel creates a top-heavy structure that can easily tip over when funnel lid is opened. Below are several options to help stabilize waste containers using safety funnels and minimize risk of tipping. Use a stand or secondary container to stabilize the waste container. Safety funnel manufacturers will often have kits available that provide a secondary container and stand to stabilize the funnel when in use. EHS offers 1-gal plastic pails on the EHS Safety Supply Store that will fit the 1-gal HDPE utility jug and provide additional support and secondary containment. Lining the bottom of the 1-gal pail with 2-3 inches of sand will further improve the stability of the safety funnel. Use a coated bottle weight. These malleable lead weights can be placed onto the neck of the waste container to add stability.
