Eight steel companies exceeded the 85 decibel (A-rated) limit by between 50 to 100 percent during a recent study on noise-induced hearing loss, the National Institute for Occupational Health said on Wednesday.

It said research had shown that 43 of 108 (40 percent) employees interviewed could not remember when last they were trained on noise levels and preventing hearing loss.

Sixty-two percent of them could not demonstrate the correct way of fitting their hearing protectors.

The research, which was conducted on behalf of the labour department, found that readings at one foundry went as high as 102dB (A) and at a sister plant up to 98dB (A).

At one steel plant's plate process and cutting section, a reading of 106dB was recorded.

None of the names of the eight companies' surveyed were provided in the research results.

At six of the companies, the occupational health nurses' audiometry certificates were valid at the time the survey was conducted, and in two companies the nurses' certificates had expired and were to be renewed.

The eight sites visited complied with the requirement to designate areas in the workplace as noise zones with appropriate signage.

However, it was noted that some signage was in need of cleaning and maintenance.

In general, noise control engineering options were not used to their fullest advantage, although some companies adopted good controls.

For example, one not only erected double glazing in control rooms, but also put in three doors to keep the noise out, researchers found.

Changing flame heater nozzles to reduce noise was another engineering control practice observed during the study.

"Good practice, such as identifying and demarcating noisy equipment exceeding 85dB (A) with hearing protection pictograms was observed and should be an example to follow," the researchers said.

There were several observations of poorly maintained reusable earplugs, and this indicated that employees should be trained to properly care for their earplugs.

Proper storage for hearing protection devices (HPD) should also be provided by companies for employees to achieve a sufficient level of care and hygiene.

Work place audits to check the state of workers' HPDs were practised by a few companies, and should be practised by all to achieve effective noise control, they said.

Several companies had decided to issue HPDs with a high noise reduction rating, preferably custom-made earplugs, to high-risk employees.

"This policy and its implementation should be a high priority for the iron and steel industry."

All companies had an information and training programme carried out by either qualified health and safety officers or qualified trainers.

Although all policies did not stipulate when this training should take place, it was reported by all companies that this was done within the first year of employment or when moving to a noisy department with exposure above 85dB (A).

Four companies reported that they conducted re-training on identification of a five percentage loss of hearing, although only in a small number of cases was evidence of this found in the employees' files.

Forty-three out of 108 (40 percent) of the employees interviewed could

not remember when they were last trained, indicating that the level and/or frequency of training needed to be improved in most companies.

The study followed the labour department's comment that immediate intervention was needed in the iron and steel industry, after compensation totalling R194 million in that sector was paid for the 2011/2012 financial year.