Safe Fruit and Veg in Brazil (Sao Paulo) ?

It would be tough to even know where many come from and what has been used.
Wash all and hope for the best.
As tech increases many find chemicals that have been used for years are now banned. Another concern is the "run off" of the chemicals in the drinking water.
I use to consume a lot of fruits and veggies, but very picky here.
I do go to local farm markets to ask about the items, but in supermercados, who knows?

The most serious recent food contamination issue in Brazil had nothing to do with chemicals.  It was outbreaks of Chagas Disease in the state of Pará, caused by açaí pulp crushed in unsanitary conditions,  that carried the parasite.   Biological contamination, not chemical contamination, is far and away your biggest threat.
As Tex says, your best safeguard is a thorough washing of raw vegetables.   Eat food that's thoroughly cooked.  Don't eat anything that's warmed over, unless you can vouch for how it was stored.  Don't eat street food.  As for fresh fruit, the age-old rule is, if you can peel it, you can eat it.  If you can't peel it but can wash it thoroughly, that may do.  If you can't do either,  leave it alone.

All you need to do is to look after Organic and Fair Trade Growers out here.

http://www.agricultura.gov.br/assuntos/ … -organicos

And for packaged groceries, we follow the US Standard on Labeled ingredients.  Thanks in a great deal for the efforts of Mr Ralph Nader, who championed this back in the 60's on what became  landmark acts on the Clean Water Act and the Food Labeling Act.

Speaking of Sao Paulo, most of the produce made available at the Cantareira, CEAGESP, Lapa, Santo Andre, Pinheiros, and Ipiranga wholesale markets ( where you can actually purchase retail, no membership required ),  is sourced through what is left of Sao Paulo's Greenbelt, which these days is mostly concentrated on Mogi das Cruzes. 

It used to be the Nisseis and Sanseis controled this market down to retail, where you sourced your fresh fruits and vegetables at your neighborhood weekly's farmer market ( Feira Livre ).

The milkman is gone for years, in fact we never had it, other than your local grocer deliveries.  I still remember being able to drink milk out of a glass bottle as a toddler. 

Still, quality produce, dairy, eggs, fruits, can be sourced locally if you care about nutritious content, pesticides, with a little bit of effort.  As matter of fact you might find this information published somewhere. 

All of this ban lift  does is to make it easier for soybean and corn growers to harvest GMO grains with your dose of pesticides, your Monsanto garden variety type.  Which is mostly for exports. China mostly. Europeans won't touch the stuff.

All you really need to to is avoid packaged and processed foods, which being said, is easier here than Stateside.   

The weekly farmer's market is a good place to start and you should develop some relationship with your stall vendor. 

Further, if you need to get a clean bill of health on your consumed meat, then check with the local rabi, I am sure they keet tabs on who does it Kosher.