When looking at investment property, pet odors smell like money.I bought one of these a few years back and was prepared for chemical warfare. 

Now when you walk it there is a very strong chemical smell and we can’t pinpoint what it is.

I bought synthetic mattress covers that are supposed to take care of this, however I did see this product on shark tank:https://buggybeds.com I've never had any "bug" related issues in 3 years.Mike

If it's the flooring I'm thinking of (the synthetic tiles that click together that are completely waterproof), you might not even have to pull them up.I've had water get under those in my own house from a plumbing malfunction, to where the whole floor was floating.

Electricity, chemicals, scaffolding, spinning blades, etc. 

Cleaning the air handler coils when dirty, changing filter, using A\C pan tabs, blowing out the drain line with shop vac and using chemicals to deter growth in drain lines all seem to help. 

Oil is used to pave roads, make plastics, produce solvents and other chemicals.

We heard from a garage door contractor he would not put in his garage doors knowing a pool would be in there since the parts get corroded from the moisture and chemicals. 

The tenant wants the guy evicted, she doesn't (shouldn't) have to breathe these chemicals while on the property.  

I would put it in the lease that the tenant needs to pay for upkeep like the chemicals and making sure it is clean.