@Bret Allen We provide the house pest-free and will re-treat if reported in the first 30 days.Our lease has had the term "any additional or periodic pest control is the responsibility of the tenant" for at least the 11 years I've been here, and it has been vetted by our attorney.I understand your opinion may differ, but I would rather have a tenant raise the issue of being responsible for their own cockroach problem (we do SFH, so neighbors don't play in) than being named in a suit for damages because somebody had a fatal reaction to our pest control vendor's choice of chemicals. 

What about household chemicals which are considered toxic or flammable , will these be considered a breach of lease?

The enzyme products work chemically to change the urine into something that is harmless and does not smell bad.  

I personally don't use a lot of chemicals around my children & would hate for a tenant's family to be adversely affected by my pest control.

Certain chemicals can make the water unpotable. 

Ask them if they're okay with the smell of the orange natural cleaner (odds are these guys will also be afraid of chemicals). 

We were successful with a new chemical treatment. 

Things like old ovens, random chemical waste, excess trash left behind by a tenant, etc.I used to drive a sedan and I was able to make that work, but having a truck is just a bit easier, in my opinion.

We hired a pest company that used a new chemical treatment at the time, which would have been about 2013. 

The prognosis from the cleaning crew was that the chemicals they would need to use to clean it, probably wouldn't make it very safe as a fridge for food afterwards.