On-Site Audit for Chemical Supplier

We started doing random on-site  (us being customers) audits of our critical suppliers. Most suppliers use a GFSI scheme or something similar, so its pretty easy to know what to look for. 

My question is I want to do an audit of the chemical suppliers warehouse and facility. They are not the manufacturer (they sell multiple brands of chemicals), more a storage and distribution hub (basically a middleman).

What should I look for? I want to be able go in with clear objectives. I can basically do a GMP audit of their place, but since its not really food, but chemicals (cleaning) it doesn't make sense to look for some things. 

I do not think they have any third party certifications of policies/procedures. (is there even a such thing?)

Any guidance would be helpful. 

Years ago I did chemical storage and also chemical manufacturing audits.

There are actually a number of certifications that manufacturers may have in place but for what you are doing I would take a look at what you would do for a food storage facility and modify your existing audit format to fit.

You will want to add things like separation of flammable, non-flammable, food grade, non-food grade, toxic, etc.  And then also add in separation based on exposure meaning you are looking for any chemicals that if exposed to moisture or air that could be combustible.

What are protections in place to protect the employees and visitors from ruptures, what does the company do to protect the surrounding community, etc.

Frankly, these days with liability being what it is, my suggestion is that you contract with a company that does these type of audits - they are well worth it.

Thanks Glenn.  What you said is pretty much what I figured I would do (modify my regular audit). The supplier has changed hands/management a few times since we've had them. I think the current owner/company is a bit shady (customer service wise). I'm trying to have him up his game and change for the better before we drop him like a hot potato and go with one of the bigger/well known companies (Ecolab, Diversey, Zep, etc).