Disintegration of Schott Bottle Lid

39. (2004)

A recent incident occurred on campus where the lid of a Schott bottle disintegrated after repeated microwaving.  The Schott bottle and lid were being used to heat agarose in a microwave and the operator sustained burns to the hand after hot agarose leaked out through cracks in the lid. 

The blue lid of the Schott bottle disintegrated in a ring around where the top of the bottle connects with the lid (see Figure 1).

Figure 1 – Schott bottle lid

Users of Schott bottles should be aware of the potential for the lids to disintegrate after repeated use.  Lids should be carefully examined for deterioration, in particular if the plastic looks faded, chipped or brittle.  Lids showing signs of deterioration should be discarded and replaced with new lids. 

Officially the company, Schott Garsco Pty Ltd, regards the lids as having a finite life span and recommends their replacement as soon as cracks or other deterioration appears.

Blue Schott bottle lids can be heated to 140oC.  Their melting point is 165oC. 

Rather than microwaving agarose with the lid on the Schott bottle it is suggested that several tissues be used to plug the neck of the bottle during heating.  This will reduce the need to microwave lids, and also prevent build up of steam and pressure in the bottle if the lid is on too tight.