Vol. 22, No. 2
Books and Publications
Publication from the World Health Organization
Flame Retardants: Tris(chloropropyl) Phosphate and
Tris(2-chloroethyl) Phosphate, Environmental Health Criteria No. 209
1998, xix + 106 pages (English with summaries in French and Spanish),
ISBN 92-4-157209-4, CHF 27.-/USD 24.30; In developing countries: CHF
18.90, Order No. 1160209.
This book evaluates the risks to human health and the environment posed
by exposure to three flame retardants: tris(l-chloro-2-propyl) phosphate
(TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and tris(2-chloroethyl)
phosphate (TCEP). In view of their many similarities, TCPP and TDCPP
are covered together. Data on all flame retardants are extremely limited
and largely confined to studies of environmental levels and adverse
effects detected in experimental animals and in vitro test systems.
The monograph on TCPP and TDCPP describes manufacturing processes and
summarizes current uses. The vast majority of TCPP is used in rigid
polyurethane foams, with main applications in insulation for buildings
and in refrigerator casings. TDCPP is likewise added as a flame retardant
to polyurethane foam and has some additional applications as a flame
retardant for nonwoven fabrics. For both chemicals, studies show that
residues are found infrequently and at low concentrations in food items.
For TCPP, traces have been detected in industrial and domestic effluents,
but not in surface water or drinking-water. Traces of TDCPP been detected
in sewage effluent, river water, seawater, drinking-water, water sediment,
and fish. In view of the low volatility of both chemicals, the report
concludes that human exposure from these sources will be very low and
will not present an acute health hazard for the general population.
Likewise, no adverse effects on the environment are anticipated from
the use of either of these flame retardants.
Experimental studies of TCPP in laboratory animals demonstrate low
to moderate toxicity by the oral, dermal, and inhalation routes. Tests
indicate that the chemical is neither a skin nor an eye irritant. No
studies were available to evaluate reproductive toxicity, immunotoxicity,
or carcinogenic potential. In vitro and in vivo mutagenicity studies
produced negative results.
Toxicity studies of TDCPP show low to moderate acute toxicity by the
oral route and low acute toxicity by the dermal route. The report found
no evidence of teratogenicity or mutagenicity. A single carcinogenicity
study found an increased occurrence of several tumors at all exposure
levels tested in both male and female rats. In the absence of data on
the mechanisms of carcinogenic action, the relevance of these findings
to humans could not be assessed. The limited studies of occupationally
exposed workers were judged inadequate for evaluation.
The second monograph evaluates TCEP, a flame retardant with declining
uses in the production of liquid polyester resins and in textile back-coating
formulations. Traces have been detected in river water, seawater, drinking-water,
sediment, fish and shellfish, and in a few food items. Experimental
studies show low to moderate acute oral toxicity. In repeat dose experiments,
TCEP caused adverse effects on the brain, liver, and kidneys. The report
concludes that TCEP is not an irritant to the eye or skin and is not
teratogenic, although some adverse effects on the fertility of male
rats and mice have been demonstrated. Data indicating low environmental
exposures support the conclusion that TCEP poses a very low risk of
adverse health effects for the general population. Use of TCEP is not
expected to cause any adverse effects on the environment.