Bonding poly (plastic) drums during flammable liquid pouring

[Poindexter2291]

Hello,

I have a question about bonding and grounding of nonconductive containers. At my job we have a poly drum that we use for bulking flammable lab solvents. The solvent mix contains a small amount of strong acids so we've had to switch from metal to poly drums, and I am not sure what is considered adequate bonding (per OSHA, but also in practical terms). I have read an OSHA interpretation letter from 1999 that says that static charge needs to be equalized/eliminated between any two containers (including nonconductive containers such as poly drums). In this letter, they "permit" two methods:

1)metallic suction pump and draw tube

2)metallic, self-closing faucet

The drum is stored in a flam cabinet. We currently use a metal funnel that has a lid that can close and clamp shut. We have the cabinet grounded, and I have bonded the cabinet to the metal funnel. I am wondering if this meets the second condition? In other words, is a funnel a "faucet?" Semantically I think they are different things and have different uses, but I think the fact that it is a metal device at the entrance to the container means it serves the same purpose in terms of fire prevention. I think it would be easy to justify but figured I would put the question out there. I used to bulk flammable acids into poly drums regularly at a previous job and we NEVER bonded or grounded any poly containers. I also want to change as little as possible regarding the procedure for how employees bulk the material into the drum, so I'm hoping to avoid having to buy complicated equipment that takes additional time or steps to set up. 

My second question is, is this adequate bonding from a safety standpoint? It would equalize charge between the funnel and the cabinet, but what about between the funnel and the poly drum itself, or between the drum and the liquid that is already inside the drum? You can build charge differential between any 2 surfaces (solid OR liquid), so I'm wondering if bonding only the funnel is adequate in dissipating the charge? It was easy when the drum was metal, we just bonded straight to the drum. 

I feel like it would be easy to justify to an OSHA inspector, but I'm new to EHS so I wanted to get some other opinions. 

Thank you in advance for any advice. 

[AnthonyB]

Hi,

This is a UK site so can't advise on OSHA issues - although do note that in our guidance we use 'tap' where the US guides would say 'faucet' and a funnel is not a tap. I'm not sure how prescriptive your codes are but here if you could demonstrate that your solution provided equal or greater safety than that in the guidance it would be accepted by our equivalent of OSHA