When sourcing brass taps, the most critical factor is the lead content. High-quality taps should be made of H59 or H62 brass, which typically contains 57-60% copper. For markets with strict health regulations like the US or EU, ensure the product is certified as 'Lead-Free' (less than 0.25% lead) to comply with NSF/ANSI 61 or EN 817 standards. Additionally, verify that the ceramic cartridge is sourced from reputable brands (like Sedal or Kerox) to ensure a lifespan of at least 500,000 cycles without leaking.