The Dow Jones industrial average was down 36 points, or 0.2 per cent, at 15,848 as of noon (1700 GMT) Tuesday.
The Standard & Poor's 500 index was down nine points, or 0.5 per cent, at 1,777. The Nasdaq composite fell 15 points, or 0.4 per cent, at 4,015.
NL Industries slumped 6 per cent after a California judge found the company to be among several that marketed paint they knew was harmful to children. The companies were ordered to pay $1.1 billion to 10 California cities and counties so lead can be safely removed from millions of older homes.
Boeing and 3M rose the most in the Dow.