Brady Corporation was ordered to pay more than £8,000 after failing to recover packaging waste in 2003.
The Banbury firm was created in 2001 by the merger of WH Brady Company with registered packaging producer Seton.
Several Seton members of staff left at this point - including those charged with ensuring it met packaging legislation.
No-one at Brady Corporation was passed this responsibility, despite the firm classifying as having to register with a compliance scheme.
Brady Corporation was fined £3,000 for failing to register in 2003, and £3,000 for failing to take reasonable steps to recycle packaging waste that year. It was also told to pay £2,088 in costs to the Environment Agency (EA).
EA investigating officer Sue Gebbels said: "This prosecution serves as a reminder to all businesses to ensure that compliance with environmental legislation is not overlooked when any major changes in their company structure takes place.
"Company directors are themselves responsible for ensuring their business operates legally, and this was clearly not done in this case."