Justrite’s Guide To Safe Grounding And Bonding Practices

Safety Guidetheir safety is essential.Protecting people, property, and the planet.Justrite’s Guide to Safe Grounding and Bonding PracticesDefinitionsGrounding:The process of bonding one or moreconductive objects to the ground, so thatall objects are at the same static potentialas earth; also referred to as “earthing.”Bonding:The process of connecting two or moreconductive objects together by means ofa conductor so that they are at the samestatic potential, but not necessarily at thesame potential as the earth.Recommended practices for identification, assessmentand control of static electricity to prevent firesand explosionsMost people are familiar with static electricity. They’ve heard thecrackling when removing clinging fabrics from the dryer, or they’vefelt a slight electric shock when touching a door knob or other metalobject after walking across a carpeted floor. During the winter orwhen the air is very dry, the effects of static electricity are morenoticeable, and annoying. But, did you know static discharge is alsoa major cause of industrial fires and explosions?In the United States, nearly 300 incidents are reported annually.In one such incident, a simple task of filling a bucket with toluenecaused a significant fire. The operator hung a metal bucket with awire bail and plastic handle on a globe valve during dispensing andstood back while the bucket filled. Suddenly, the toluene ignited,leaving the operator unable to extinguish the fire with a small handheld extinguisher. He left the scene to grab a larger fire extinguisher,but the fire was too large when he returned. He could no longeraccess the valve to shut off the toluene supply, providing the fuelfor the large blaze. It resulted in major property damage.Investigators identified a spark caused by static discharge startedthe fire. The ungrounded bucket’s plastic handle insulated it fromthe piping system. This led to a difference in charge between thetwo.Friction between different types of material creates static electricity.When contact is made, electrons may transfer from one materialto the other. This creates an imbalance of electrical charges.Transferring or pouring flammable liquids also generate energy,increasing the risk of static electricity.Antistatic wires for use in bonding and groundingElectrical grounding and bonding are important safety practices forpreventing static discharge and reducing the possibility of a fire. Butthe electrical principles on which we base grounding and bondingcan be confusing. This guide answers some common questions aboutgrounding and bonding, and will help you apply these principles andbest practices in your workplace.1 of 5

1.Bonding wireconnects canto funnel.Grounding wireconnects drumto earth ground.What is the Purpose of Grounding and Bonding?When working with flammable liquids, safety needs to alwaysbe top of mind. You must ground containers when dispensingClass I flammable liquids between containers. As an industrybest practice, Class II and Class III liquids should be groundedwhen heated within 30 F from a storage or process condition.As the example above illustrates, it’s easy for a spark of staticto cause a flash fire. The purpose of grounding and bonding isto keep that from occurring, by providing a conductive pathwaybetween transfer and dispensing containers and the ground.Grounding all containers to an earth source is recommended toprevent the buildup of static electricity. Attach grounding cableson any drums in use to an earth source for as long as the drumis in use. This provides a pathway for the electric charge to theearth, where it safely dissipates.When dispensing liquid into another container, use bonding wireto connect the dispensing container and the receiving container.This ensures both containers have the same static electricpotential and prevents the formation of sparks.Use bonding wire while pouring liquids into other containers.For grounding or bonding to be effective, there must be ametal to metal connection. Even small amounts of paint, rustor dirt around the attachment may affect the quality of theconnection.2. Do I Need to Ground All Flammable Liquid SafetyCabinets?There are no regulations or codes that require grounding asafety cabinet. But, it is critical to do so if you are dispensingClass 1 flammable liquids from inside the cabinet. Not onlycould the inside of the cabinet rapidly fill with ignitable vapors,the cabinet also has a large metal surface and metal shelves todischarge static against.All Justrite safety cabinets come with exterior grounding lugsin place to connect with a ground wire to a ground source.Connect a ground wire between all containers used to transferliquids and someplace inside the cabinet, like a shelf hook orvent hole.Justrite cabinets feature grounding lugs that accept antistaticwires to safely ground cabinet to earth ground.It is also an industry best practice to ground the cabinetotherwise.2 of 5

3. Do I Need to Ground Hazardous MaterialSafety Cabinets?When conditions exist where ignitable vapors, flammable gases,combustible dusts can be ignited by static, static managementshould be utilized. Safety assessments should be made by aqualified individual to determine if grounding the cabinet isrequired.4. Is Grounding and Bonding Required when TransferringFlammable Liquids Between Containers?Here is what OSHA 1910.106(e)(6)(ii) states regarding grounding:Flame arresters prevent ignition of ignitable vapors.Category 1 or 2 flammable liquids, or Category 3 flammableliquids with a flashpoint below 100 F (37.8 C), shall not bedispensed into containers unless the nozzle and containerare electrically interconnected. Where the metallicfloorplate on which the container stands while filling iselectrically connected to the fill stem or where the fill stemis bonded to the container during filling operations bymeans of a bond wire, the provisions of this section shallbe deemed to have been complied with.In summation, you must ground and bond all containers ofliquids with a flashpoint of 100 F or less. Note: The flexiblenozzle of a Type II safety can is an effective bondingconnection.5. What Part does a Flame Arrester Play in Bondingand Grounding?Flame arresters are an important safety feature to preventignition of ignitable vapors inside a safety can. They are alsointegral to the bonding or grounding circuit when ground orbond wires are attached to the outside of safety cans.6. What are the Requirements for a Bondingand Grounding Cable?Antistatic wires with alligator clips are a popular choicewhen grounding containers. Clips with their sharp teeth canbe “wiggled” to ensure metal to metal contact on paintedsurfaces.Ground/bond wires are not specified by the current-carryingcompacity. Braided or stranded wires offer robust strength anddependability when frequently connected and disconnected.Justrite uses airplane cable. Use strong clamps with sharp biteor teeth to ensure a good metal-to-metal connection Whentesting ground and bond circuits, a resistance of 1 megohm (10to the 6th power) or less is considered adequate per NFPA 77.Helpful Tip: For complete confidence in the connection, sandoff all painted surfaces.3 of 5

7.How do I Ground and Bond Plastic Drums During Transfer?Plastic drums do not conduct electricity, but static electricitymay still build up on the surface of the plastic or in theflammable liquid itself.Justrite discourages using plastic drums and containers forflammable and combustible liquids, unless provisions to managestatic are incorporated into the design or the transfer processrisks are fully assessed. Always consult NFPA 77: RecommendedPractice on Static Electricity.To properly ground when using nonmetallic containers, anantistatic wire connects the poly can’s cover assembly (withspecial internal insert) to the recieving vessel. A secondantistatic wire connects the receiving vessel to a ground pipe.To manage static electricity when dispensing flammable liquidsinto plastic drums, use Justrite’s Large Steel Drum Funnel witha 32-Inch Flame Arrester. The full-length brass flame arresterminimizes splashing, friction, and the buildup of static in thefluid. When properly connected by grounding or bonding wires,the funnel keeps the fluid at the proper static potential. Sitplastic drums on a grounded metal plate to dissipate surfacestatic on the outside of the plastic drum.8. How do I Bond Plastic Safety Cans?Plastic or polyethylene safety cans are popular because oftheir resistance to corrosion and chemical attack. They are alsoless susceptible to dents, punctures and chips than metal cans.Justrite’s non-metallic safety cans feature a carbon impregnatedinsert creating a conductive path between the stainless-steelhandle assembly and the stainless-steel flame arrester insideof the pour spout. A convenient place label on the handle issuitable for making a ground/bond wire connection between itand another container.4 of 5

Contact Justrite for Help Managing Flammable LiquidsJustrite Safety CabinetsAs a global leader in industrial safety solutions, Justrite is dedicatedto protecting where the world works. We partner with ourcustomers to better understand, anticipate and systematicallyaddress the safety issues they face every day. From the storage,containment and clean-up of hazardous materials, to spill controland emergency showers, we offer the single most comprehensiveportfolio of safety products available. For further information visitus online at justrite.com.Designed to store flammable liquids, corrosives, pesticidesand other hazardous materials.References “Bonding and Grounding: Quick Tips #255.” y-bonding-grounding-255“Flammable Liquid Storage and Handling: Quick Tips 179.” y-flammables-combustibles-179“How do I Work Safely with Flammable and Combustible Liquids(Static Electricity)?” Canadian Centre for Occupational Health and flammable static.htmlO’Brien, Mike. “Static Grounding – Dangerous, Preventable.” PlantEngineering, 15 Nov. 2010, ounding-dangerous-preventable/Patterson, Ryan. “Drawing Toluene into an ungrounded metalbucket.” Newson Gale, -bucket/Large Steel Drum Funnel with 6 inch Flame ArresterWitherspoon, Renee. “Static Electricity and Flammable LiquidSafety.” ASSP – South Plains Chapter, ctricity-and-flammable-liquid-safety/Funnels are fitted with brass flame arresters that absorb anddissipate heat.Justrite is a portfolio company of Justrite Safety Group. Justrite Safety Group is a growing family of leading industrial safetycompanies offering the world’s most comprehensive safety portfolio—from the storage, containment and clean-up of hazardousmaterials to emergency showers, industrial matting and motion safety. 2019 Justrite Safety Group Code 193 (0219)5 of 5

When dispensing liquid into another container, use bonding wire to connect the dispensing container and the receiving container. This ensures both containers have the same static electric potential and prevents the formation of sparks. For grounding or bonding to