Fossil oils - The Ecology of Building Materials - page 155

Table 9.11: The anticipated lifespan of certain
plastics

Type of plastic Assumed lifespan (years)

PMMA Less than 40

PIB 11-less than 40

PVC 8-less than 30 (1)

PE 2-15 (1)

UP 5-less than 35

EPDM Less than 30

PUR 7-10

CR 2-less than 40

IIR 2-less than 35

T 22-less than 50

Si 14-less than 50

ABS 15

MF 6-10

PF 16-18

NBR 10

EVA 3

PA 11-less than 30

PP 3-less than 10

SBR 8-10

PTFE 25-less than 50

Notes:
The evaluation includes both external and internal use and built-
in situations. Positioning within water or earth is not included.
The most protected locations achieve the best results.
(1) Does not apply to buried cold water pipes in thicker plastic,
which lasts longer, especially PE.
(Sources: Grunau, 1980; Holmström, 1984)

The vast majority of plastic products currently on the market have been
around for less than 15 years, so there is very little feedback on their lifespan.
Other products have been on the market for a longer period, but amongst the
polymer technicians it is well known that today's components are very different
from those that were used in products of 20 years ago. The design of products
has changed so much recently that it is difficult to find examples giving a picture
of the lifespan of articles and products made today.
The assumed lifespan of a plastic is based on so-called accelerated ageing tests.
The material is exposed to heavy, concentrated stresses and strains over a short
period. Dr K. Berger from the plastics manufacturers Ciba Geigy AG states that
present forms of accelerated ageing tests have a 'low level of accuracy at all lev-
els' (Holmström, 1984).