for "off-specification".

Lorsque survint l’accident fatal, il ne contenait qu’un peu plus de 300 tonnes d’ammonitrates déclassés pour cause de granulométrie (grains trop petits ou trop gros).
[http://depris.cephes.free.fr/azfan1.htm]

Les produits étaient « déclassés » à cause d'anomalies dans la granulométrie mais aussi dans la composition des produits
[http://www.ac-toulouse.fr/histgeo/monog/azf/azf.htm]

le NA stocké dans le bâtiment 221 n’est ni « propre à la livraison » il est déclassé en raison de la taille de ses granulats ni comparable à celui du bâtiment 335 B
[http://www.valeursactuelles.com/magazine/enquetes/visuarticl...]

including shed 221, in which it unequivocally authorised the storage of up to 500 tonnes of out-of-specification [sic] product or « fines ».
[http://www.atofina.com/groupe/gb/doss/detail.cfm?ID=984&arch...]

The explosion occurred in warehouse 221, a building currently used to store off-specification ammonium nitrate crystals
[http://www.saunalahti.fi/ility/AZF.htm]

The building concerned held between 300 and 400 tonnes of different
compositions of ammonium nitrate, including downgraded or off-specification material
[www.hse.gov.uk/consult/condocs/cd-nihhs.pdf]

because a product was too badly made to be sellable (off specification products)

OFF SPECIFICATION
Oil product or gas that does not meet specification. Refers either to contract specification or those benchmark specifications generally used in the physical market (The Energy & Power Risk Management Glossary)
[http://www.riskwaters.com/guides/engloss/eprmgloso.htm]

Off-specification stock Stock which is produced by errors in processing, leading frequently to customer dissatisfaction.
[http://www.swbic.org/education/env-engr/tools/glossary.html]