What is a significant disadvantage of using solder that contains lead?

The significant disadvantage of using solder that contains lead lies in the health risks it presents and the regulatory framework that governs its use. Lead is a toxic metal that can cause serious health issues, including neurological damage, especially in children and pregnant women. Consequently, the use of lead-based solders has become increasingly restricted in many regions due to public health concerns. Regulations such as the Restriction of Hazardous Substances (RoHS) directive in the European Union aim to limit the use of hazardous substances in electrical and electronic equipment, which has led to a strong push towards lead-free alternatives. This focus on health and environmental safety makes the presence of lead in solder a significant concern for manufacturers, consumers, and regulatory bodies.