Noise-induced hearing loss as an occupational disease (BK 2301)

What is BK 2301?

Annex 1 of the German Ordinance on Occupational Diseases (BKV) lists “noise-induced hearing loss” under no. 2301, in the group of diseases caused by physical agents. It means hearing loss caused by noise at work. The guidance leaflet on BK 2301 (published on 1 July 2008) defines noise as any sound that can damage hearing, whether it acts as continuous noise, strongly fluctuating noise or impulse noise.

From which level does the risk arise?

According to the leaflet, hearing damage can occur after years of exposure at a daily noise exposure level from 85 dB(A). From about 90 dB(A), a considerable share of those exposed over a long period are at risk. Frequencies above 1000 Hz and sudden sounds of high intensity are particularly dangerous. Very short peaks above 137 dB(C), for example from blows on metal, can destroy the hair cells in the inner ear mechanically within milliseconds.

A single noise event such as an acoustic trauma is legally not a BK 2301 case but an accident at work (Federal Social Court, judgment of 12 April 2005, B 2 U 6/04 R). How short, loud tasks affect the daily value is shown in Calculating the daily noise exposure level.

Which activities are typical?

• Metalworking, hammering and compressed-air tools
• Construction work and woodworking
• Textile industry and air transport
• Agriculture and forestry, and professional musicians

Typical levels of individual tasks are in the noise levels table and on the occupation pages, each with a source.

Suspicion and report

Doctors and dentists must report a well-founded suspicion of an occupational disease without delay to the competent accident insurance institution or the authority for occupational health and safety (section 202 of Social Code VII). According to the DGUV, suspicion is justified if there is noise damage to the inner ear (ICD-10 H83.3) and the insured person was exposed to noise over years or briefly to very high levels. The DGUV provides a form for the report.

How common is BK 2301?

In the same statistics, 24,340 occupational diseases were recognised in total in 2025; noise accounted for 9,819 of them, around 40 per cent.

What companies do to prevent it

• Determine noise in the risk assessment and observe the action values of 80 and 85 dB(A) (overview of the duties).
• Reduce noise at the source first: hierarchy of measures.
• Provide suitable hearing protection and have it worn for the whole noise exposure. If a hearing protector is worn for only four hours of an eight-hour day, its effective protection is at most 3 dB (DGUV Rule 112-194, section 7.6).
• Arrange or offer occupational health checks.
• Train workers, with practical exercises.