Manual filling and weighing processes

Status:

completed 02/2004

Aims:

In many areas of industry, base materials and aggregates which are dust-raising and in some cases highly toxic or carcinogenic are weighed out manually before being fed into mixing systems. When the shipping containers (e.g. sacks) are opened, the materials poured in, the containers put down or to one side, etc., dust emissions arise which in some cases may be substantial. Particularly high levels of dust are raised when empty sacks are compressed in the working area in order to reduce their volume prior to disposal, and when dust deposits are swept up.

Dust thus enters the working area from a large number of different sources. These various emissions can generally be collected (vacuumed) only in the area in which the materials are poured into the mixtures. The dust emissions arising in the vicinity flow to the suction point (flow sink), where they cause further exposure for the employees. These requirements give rise to problems for the areas of machine safeguarding and fire and explosion protection. Ergonomic exposure issues must also be considered during manual handling of the shipping containers (picking up, putting down, pouring out, etc.). Working processes had therefore to be developed which prevent dust from spreading. Handling of the shipping containers must be simplified, and disposal of empty containers must take place within closed systems.

Following co-ordination with the BGs concerned, an interdisciplinary project was conducted for the description of general protective measures. These measures were aimed to be suitable for straightforward and economic implementation, in particular by SMEs. Consideration was given to the wide differences between filling methods according to the quantity of mixtures and the frequency of the mixing processes. The quantities to be filled range from several kilograms (for example during the manufacture of brake shoes, with a total mixture quantity of up to a ton) down to the order of grammes (mixture of paint pigments). The filling frequency ranges from once per day or week to several times per shift. The mixture recipes may also be subject to continual change.

Activities/Methods:

Notes were first exchanged in order to identify and pool the excisting expertise in the BGs. Practical experience was gained in affected businesses. Checklists for hazard identification were drawn up based upon the results of the study. The checklists constitute a practical aid to the implementation of organizational and technical measures.

Results:

The expertise of the BGs and practising professionals within companies formed the basis for the results as presented. Preliminary results were presented at the G3 seminar held in 2002 on the subject of hazard avoidance during filling and weighing. The seminar was also used for the gathering of further information and practical experience from the affected companies. Based upon information thus gained, checklists were drawn up for hazard assessment at workplaces involving manual filling and weighing processes with regard to the following aspects: working areas, ventilation facilities, aisles, organizational requirements (including first-aid systems, instruction of personnel, personal protective equipment, hygiene), agents (handling of hazardous substances, handling of biological agents, fire and explosion protection), and handling of loads.

Owing to the wide range of information, the working group decided to launch a follow-up project for the production of an interactive software application for hazard analysis at filling and weighing workplaces based upon these checklists. The software is to contain the essential statutory principles, practical tips, and other information, and support the user in the conducting of hazard analyses.

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