ASTM revises lead safety limits in steel products

The World Health Organization (WHO) has long been calling for a ban on the use of lead in various products such as paints, cosmetics, toys, steel and building materials. This is because lead is hazardous to human health as well as to the environment. The International Agency for Research on Cancer (IARC) has classified inorganic lead compounds as “probably carcinogenic to humans.”
In line with this, ASTM International has revised its lead usage limits in steel products under standard A653/A653M-15 and A755/A755M-16 for galvanized and color-coated steel sheets, respectively.
Elaborating on the new revisions, Gary Dallin, chairman of A05.07 committee, ASTM International, said: “In line with the Saudi Vision 2030, these developments are viewed as significant reflecting the efforts of a non-oil base industry as being a proactive contributor to meet the best international practices.”
Formed in 1898, ASTM International is one of the world’s largest international standards organizations. It seeks to enhance performance and help consumers have confidence in the things they buy and use — from the toy in a child’s hand to the aircraft overhead.
Over 12,000 ASTM standards are used around the world to improve product quality, enhance health and safety, strengthen market access and trade, and build consumer confidence.
ASTM has over 30,000 volunteer members from more than 140 countries who are producers, users, consumers and general interest parties. It is these members who decide which standards development activities to pursue.
There are currently 55 members from Saudi Arabia across all ASTM committees, including one member in committee A05.
“The basic rationale for the ballot was to have it formally specified in A653 that lead is not needed whatsoever in the zinc used to coat steel sheet, even though North America and other parts of the world have been using lead-free zinc to produce galvanized sheet for over 20 years,” said Dallin.
“For coated sheet, lead has negative effects on appearance, the ability to produce an extra smooth coating and corrosion resistance of the coating. At levels of approximately 300 ppm and higher, lead produces an increasingly larger spangle that is unwanted and detrimental for many applications. Excessive lead can also contribute to selective spangle darkening which results in a mottled appearance.
“Furthermore, lead levels of even 100 ppm in zinc coatings can result in an increased rate of spangle boundary corrosion in humid, warm environments, which can create a problem known as ‘delayed adhesion failure of the coating’,” he added.

Source: Arab News