A government research centre in Suffolk breached health and safety rules on cancer-causing substances during an inspection in 2007.
The Centre for Environment, Fisheries and Aquaculture Science (Cefas) in Lowestoft has accepted a Crown Censure.
It is the equivalent of a prosecution of a government body.
The Health and Safety Executive (HSE) found it failed to assess and control the substances but said there was no evidence of harm to any employee.
The breaches were revealed during investigations by the HSE in October 2007 at the Cefas laboratory in Pakefield Road, Lowestoft, which employs more than 320 people.
It identified failings in the assessment and control of hazardous and carcinogenic substances.
Inspectors also identified that Cefas had failed to provide enough health surveillance between 2005 and 2006.
The HSE said the failings had since been remedied.
The censure was accepted on the basis that while the investigation identified failings in the management and control on hazardous substances, there was no evidence of harm to any employee, nor was there evidence of a defined, identified risk.
HSE inspector Steven Gill said: "This case highlights the need for employers to properly manage hazardous substances and the need to protect the workforce through assessment, control and appropriate health surveillance for these substances.
"This applies to government agencies like Cefas as much as it does to any other employer."