PCBs ceased to be added in 1974, but the use of existing stocks containing PCBs continued on construction sites until about 1980. The caulking compounds containing PCBs varied in colour from grey through to black. The normal life of a caulking compound is 15-20 years when replacement may be required. This can depend upon the environmental conditions and where they are used. All buildings having expansion joints and built between the 1940s and the late 1970s are likely to contain PCBs in the caulking compound.
Analytical laboratories can determine whether the caulking compounds contain PCBs.
Unless the original supplier or laboratory analysis confirms the absence of PCBs, it may be prudent to assume the presence of PCBs in the caulking compound. The WorkSafe Western Australia Commission has stated that if the concentration of PCBs is greater than 50 parts per million in solids or liquids, they should be considered contaminated and may require special procedures for handling and disposal. Bitumen caulking compounds Bitumens have also been used as caulking compounds, mainly on roads, footpaths or other horizontal expansion joints. Bitumens are always black in colour and in general do not contain PCBs. The bitumens are identified by their high flexibility and that they can be stretched.