Agricultural seed producers typically have full disclosure on their seed packs, including date of manufacture, lot #, etc. Additionally, they will state terms and conditions for replacement. (Ie - )
I can say that I've had 1,500 acres worth of Bell Pepper seeds replaced before, but not without a fight, and only after being able to prove a problem down to a particular lot#.
If the weed market ever follows the lead of Agriculture, expect that growers will have to document every aspect of every grow, as well as be prepared for surprise audits at any time. The production of food (and drugs) is regulated, although it's only been in recent years that demands of food safety and produce traceability have started becoming mainstream. In today's marketplace (of fresh produce) if a grower/packer/shipper is not third-party audited don't expect to sell your produce at a sustainable price because none of the Retailers, Wholesalers, Foodservice nor Processors will want it.
Think about it this way, if someone died while consuming the product you produced then who is responsible? Food safety programs are a PITA, but ultimately act as an umbrella of coverage for the grower. By being able to show, in a court of law, that YOU are not responsible because everything had been documented and used in accordance with label specifications and produced with generally accepted methods then you are directing the potential liability elsewhere. Lawyers always tend to go after perceived "deep pockets" but have to start with the growers.
Currently, there is a Produce Traceability Initiative being implemented that not only requires third-party audits but also requires specific information to be put onto each case. Said information allows the trace back to the grower, field, etc. Not unlike weed, fresh produce goes thru many hands before it ends up on the grocery store shelves. Contamination can occur anywhere along this path. Documenting your piece in this puzzle is the only way to avoid costly lawsuits, and potentially time behind bars, should a consumer die from eating your goods.
Sorry for getting a little off-topic, but if we ever expect weed to become legalized and mainstream, then issues like these will have to be addressed. This all starts from the seeds the growers use to produce their crops, so if I were a breeder I think I'd be looking at the commercial agriculture market and would follow their lead - all starting with labeling seed packs and documentation.
