Compliance varies significantly by region. For the US market, ensure garments meet CPSIA lead and phthalate standards for any plastic or metal trims. For the EU, REACH compliance for dyes and chemicals is mandatory. Regarding sizing, clubwear is notoriously inconsistent; you should provide your own detailed size charts (XS-3XL) and require the factory to follow tolerance levels of no more than 1-2cm. Since clubwear is often marketed globally, sourcing from suppliers who offer 'Western Sizing' patterns rather than 'Asian Sizing' is crucial to reduce return rates.