A ten-minute test that costs just $6 uses a selective chemical reaction, involving mixing paint samples with solid potassium molybdate in ammonium acetate to form a turbid suspension of lead molybdate and a simple, portable turbidity meter to determine the lead content based on the resulting level of opacity.

The test will be important in allowing contractors to comply with the new EPA Lead Renovation, Repair and Painting Program regulation that means any house built before 1978 must be tested for lead contamination in paint prior to any professional renovations or repairs.

• Field turbidity method for the determination of lead in acid extracts of dried paint
  W. Studabaker, M. McCombs, K. Sorrell, C. Salmons, G. Brown et al.,
  J. Environ. Monit. 2010, 12.
  DOI: 10.1039/c000888e