A:
|
For the purpose of regulated
environments, all polymer standards have an expiration date that is set at two
years from the product purchase date. Polymer molecular weight
standards are very stable when handled according to the instructions
and procedures described in the Polymer Standards Users Manual
(delivered with every shipment.)
Polymer molecular weight standards are generally delivered with
sufficient material for multiple standard preparations. Any unused
portions remaining after the container has been opened should be stored
in accordance with prudent laboratory procedures; Polymer Standards
Service-USA, Inc places emphasis to the following:
Store polymer
compounds in a cool, dry and dark environment.
Do not expose the standards to UV radiation.
Prevent undue stress on the molecular weight standards during sample
dissolution and/or actual testing (including, but not limited to,
shaking, high-pressure filtration, exposure to ultrasound and or
microwaves).
There are many storage variables outside of the control of Polymer
Standards Service-USA, Inc. Therefore, Polymer Standards Service-USA,
Inc. cannot provide information about, and makes no warranties
concerning the continued suitability of previously opened reference
polymers. Decisions concerning the proper use of polymer standards are
the responsibility of the end purchaser.
Polymer Standards Service-USA, Inc reference polymer molecular weight
standards do not carry expiration dates in the traditional sense;
rather our general stock of polymer molecular weight standard (stored
in controlled facilities) are granted official status (periodic
re-certification of polymer molecular weight) under the authority of
the Quality Control process at the PSS Polymer Standards Service Gmbh
(ISO certified) manufacturing facility.
The posted expiration dates reflect the minimum durability time of a
polymer molecular weight standard that has undergone less than ideal
storage and handling conditions.
|