22 | February 2020
By Robert J. DeMalo, M.Sc., EMSL Analytical, Inc.
Background
M
ost people are aware that exposure to as-
bestos or polychlorinated biphenyls (PCBs)
can be hazardous, but far fewer know that
some types of caulking used in the past con-
tain both asbestos and PCBs. In fact, there
are reports that indicate some caulking compounds used to
build and renovate buildings up until 1979 had considerable
concentrations of each of these materials, both designated
by the U.S. Environmental Protection Agency (US EPA) as
Hazardous Air Pollutants (HAPs). Exposure to both asbes-
tos and PCBs can lead to adverse health effects. Asbestos
is designated as a Group 1 Carcinogen by the International
Agency for Research on Cancer (IARC) and exposure is
known to cause Lung Cancer, Mesothelioma and Asbesto-
sis. Exposure to PCBs and dioxin-like PCBs can affect the
immune system, reproductive system, nervous system, en-
docrine system and is also designated as a Group 1 human
carcinogen by IARC.
Caulking and caulk products are elastic sealant materi-
als that are used to fill cracks and joint gaps and are used
to seal windows against drafts. Caulking and caulk prod-
ucts were commonly used both indoors and outdoors and
were applied in both residential and commercial settings to
seal windows, door frames, boilers, pipe joints, masonry
columns, building joints and exteriors. Caulk products were
designed to be weather proof, pliable, resistant to heat and
water and to be durable, which is why both asbestos and
PCBs were used in its formulation due to their respective
beneficial properties. Asbestos was added to caulking and
caulk products from roughly 1950 to 1979 and the US EPA
estimates that caulk used in this time period can contain up
to 25% asbestos.
Polychlorinated Biphenyls (PCBs) are regulated by the
Caulking: Does It Have Asbestos or PCBs…
Or Both?
