The Victorian EPA has slapped two fines on a Benalla timber mill D&R Henderson after an explosion last November

Particle board maker Monsbent Pty Ltd, which trades as D&R Henderson, was issued with fines totalling $16,532 by the government watchdog.

They followed an explosion on the afternoon of November 3 which was reported to the hotline by a concerned member of the public.

EPA North East Regional Manager Renee Palmer said the caller described a plume of smoke rising from the site on the northern edge of Benalla.

"The explosion took place inside the facility, the local CFA brigade was called to the premises and WorkSafe was notified, but the company did not report the incident to EPA," Ms Palmer said.

"It's a legal requirement for any company operating under an EPA licence to notify EPA of any breach of their licence conditions, and that is a clear responsibility, it's in writing on their licence."

Monsbent was fined for not reporting the incident, considered an unlicensed discharge and therefore notifiable, to the EPA and for having a monitoring plan that was inadequate to satisfy the conditions of its EPA licence.

The penalty figure of $8261`is the highest EPA fine possible for a corporate body without the matters going to court.

In January last year, Monsbent was fined $8060 by the EPA for making unauthorised modifications to timber chipping equipment at its Benalla factory.

The company's operations manager was unavailable on Monday to comment on the latest fines.

Charges alleging safety breaches have also been laid by the Victorian Workcover Authority in relation to the death of worker Rasta Kemp at the mill in 2018.