Section 5. Handling and Storage
The storage of polyester resins is subject to the requirements of the Highly Flammable Liquids and Liquified Petroleum Gases Regulations, which include:
i) Polyester resin storage must either be in the open air and covered with polythene and preferably away from direct sunlight, or in a store which is a fire resisting structure, or in a store in a "safe position" (not defined but may mean isolated). Provision must be made for any spillage to be contained. Stores or storage areas must be boldly marked "Highly Inflammable".
ii) The quantity of polyester resin kept in working areas must not exceed 50 litres (approx. 60 kilos) and must be kept in closed vessels in a fire resisting leak proof cupboard or bin.
iii) Conveyance from stores to working areas should preferably be through a totally enclosed pipework system. Closed vessels designed to avoid spilling or leakage may be used where this is impractical.
Polyester resin will polymerise and gel if not stored correctly. Resin should preferably be stored at temperatures not higher than 20?C (68?F) when the shelf life of most grades will be six months minimum. Very low storage temperatures result in long shelf life but a large increase in resin viscosity, and for many applications cold resin must be brought to workshop temperatures before use. Water must be excluded from all storage containers as this causes slow curing, and will also cause rust to form in steel drums and tanks. Rust is also a cause of premature gelation.
