Investing in product testing is like investing in an insurance policy. It may not be a fun way to spend your hard earned dollars, but you must invest in it. Ultimately, this product testing will protect you as it will bring to light any issues that might be of serious consequence to the success of your product and help you to uncover them and correct them early on, thus affording you the opportunity to do business with retailers large and small. Imagine the alternative: you go to market without testing and later find out you must recall your product. So, instead of fighting this process, go with it, knowing that it is an investment in your business.
To determine what product testing you must do, start with the Consumer Product Safety Commission:
Also, if you have access to a large retail buyer within your product category, ask them for their advice.