Supermarkets seem able to sell veg and fruit sozzled in chemicals 
'Sozzled' may be slightly exaggerating
The range of products that can be applied to many crops now are getting limited (and in some cases very limited).
Commercial growers are heavily regulated with what they can and can't put on crops. If the growers are found to have over applied a product they can fail any QA scheme check which results in the product being refused and if its a Dept check they can loose part of the farm payment.
Crops will be tested for MRL's on the shop floor too - if found to exceed an MRL the product is withdrawn from the shelves.
Without chemicals we wouldn't be able to have such an array of crops to feed the world.