BRITISH STANDARD BS EN 14958 2006 +A1 2009 Food processing machinery — Machinery for grinding and processing flour and semolina — Safety and hygiene requirements ICS 67 260 ��������� � ���� ����������[.]
General
Machinery must adhere to the safety requirements and protective measures outlined in this clause Furthermore, the design of the machine should align with the principles of EN ISO 12100:2003, addressing relevant but not significant hazards that are not covered by this European Standard.
For hazards which are to be reduced by the application of the type B standards such as EN 294,
According to EN 349, EN 614-1, EN 811, EN 953, EN 1088, EN 1672-2, and EN 13284-1, manufacturers are required to conduct a risk assessment to determine the requirements of the type B-standard This specific risk assessment must be integrated into the overall risk assessment of the machine.
Mechanical hazards
The following safety requirements for the prevention of mechanical hazards apply:
fixed guards shall comply with EN 953 !Fixing systems for fixed guards shall remain attached to these parts or to the machine when the guards areremoved;"
NOTE In general movable guards are not considered for the machines in the scope because of the nature of the process
if the manufacturer adopts as an alternative a movable interlocking guard, this guard shall comply with
EN 953 and 1088 In that case the possible need for interlocking with guard locking shall be defined on the basis of the risk assessment;
safety distances shall be in conformity with EN 294, EN 349 and EN 811
To ensure safety, access to hazardous areas at product inlet and outlet openings must be restricted through proper connection to auxiliary equipment or other machinery The user instructions should provide clear guidelines for making these connections correctly.
Access shall be prevented by fixed guard(s)
Access during the normal operation shall be made impossible by means of fixed guard(s)
Access to this zone during normal operation, such as for product verification, is permitted only at the out-feed side of the rolls An internal fixed guard must be installed to prevent access to danger points, in compliance with EN 294 (Tables 3 or 4) Consequently, the external door providing access can be movable without the need for interlocking.
Access to the roll drive arrangement on the same floor as the equipment must be restricted by fixed enclosing guards Additionally, access to the portion of the roll drive arrangement located below that floor should also be blocked by fixed enclosing guards, except for danger zones that are situated more than 2.7 meters above the lower floor, in accordance with EN 294:1992, 4.1.1.
Access to the danger zones of pneumatic pistons of roll engaging or disengaging device shall be prevented by fixed enclosing guards
5.2.2.5 Zone 5: grinding rolls transmission drive
Access to the grinding rolls transmission drive (belt, gear or chain) shall be prevented by fixed guards
5.2.2.6 Zone 6: feeding rolls transmission drive
Access shall be prevented by fixed guard
Access shall be prevented by fixed guard
Access shall be prevented by fixed guard
Access shall be prevented by fixed guard
In order to avoid possible hazard of instability:
the machine shall be laid out so that the period of starting phase be limited as much as possible;
the design of the control system shall prevent a new start before the machine has stopped completely;
Detectors installed on the machine monitor for any sliding or gliding movements If the amplitude of such movements surpasses the normal threshold, the detectors issue a stop instruction to halt the machine's operation.
For machines operating in areas with heightened earthquake risk, it is advisable to install security ropes designed to maintain the stability of the plan sifter under a load that is at least six times the static weight.
5.2.4 Air classifier (purifier) (see Figure 8)
The access to the moving parts shall be made impossible by means of fixed guard
The design of the control system shall prevent a new start before the machine has stopped completely
The machine shall be laid out so that the period of starting phase is limited as much as possible
The rotor shall be completely enclosed inside the housing Access openings shall be closed by fixed guards
The access shall be prevented by fixed guard
The screw shall be completely enclosed inside the housing Access openings shall be closed by fixed guards
The access shall be prevented by fixed guard
Where no access is required access to the rotor shall be prevented by means of fixed guard
Where access is required a door without interlocking can be used assuming that the sieve cover acts as a fixed guard with openings in compliance with EN 294:1992, Table 4
5.2.6.2 Zone 2: rotor drive belt transmission
Access shall be prevented by fixed guard
The rotor shall be completely enclosed inside the housing
5.2.7.1.2 Zone 2: rotor drive belt transmission
The access shall be prevented by fixed guard
The rotor shall be completely enclosed inside the housing
5.2.7.2.2 Zone 2: rotor drive belt transmission
The access shall be prevented by fixed guard
Zone 5: grinding rolls transmission drive
Zone 6: feeding rolls transmission drive
Figure 6 — Hazard zones in the roller mill
Figure 7 — Hazard zones in the plan sifter
Figure 8 — Hazard zones at air classifier (purifier)
Zone 2: motor drive belt transmission
Figure 9 — Hazard zones in the air classifier (aspirator)
Zone 2: motor drive belt transmission
Figure 10 — Hazard zones in the rotating machine
Figure 11 — Hazard zones in the impact machine (impactor)
Protective measures against electrical hazards
All electrical equipment associated with the machine shall comply with the requirements of !EN 60204- 1:2006" as indicated in this clause
Live components must be housed within enclosures that ensure protection against direct contact, achieving at least an IP2X rating as specified in EN 60529:1991 Access to the enclosure should only be granted through the use of a key or tool, or by disconnecting the live parts prior to opening, in accordance with options a and b of EN 60204-1:2006.
To ensure protection against indirect contact resulting from insulation failure between live and exposed conductive parts, it is essential to connect exposed conductive components to protective bonding circuits and to disconnect the supply as specified in EN 60204-1:2006.
5.3.3 !Degrees of protection (see 11.3 of EN 60204-1:2006)""
Enclosure of control gear shall provide a degree of protection at least IP54
The cable sections shall be according to that indicated in !Annex D of EN 60204-1:2006" and the identification of the cables shall be in compliance with 14.2 of EN 60204-1:1997
The manufacturer must implement effective measures to prevent the hazardous buildup of static electricity Additionally, if required, the manufacturer should provide guidelines for the machine's installation in compliance with EN 1127-1:1997, section 6.4.7.
5.3.6 Safety requirements related to electromagnetic phenomena
Machines must possess adequate immunity to electromagnetic disturbances, ensuring safe operation as designed and preventing dangerous failures when subjected to the levels and types of disturbances specified by the manufacturer.
The manufacturer of the machines shall design, install and wire the equipment and sub-assemblies taking into account the recommendations of the suppliers of these sub-assemblies.
Noise reduction
Incorporating noise reduction into the design process is essential, with a focus on source-specific measures as outlined in EN ISO 11688-1 The effectiveness of these noise reduction strategies is evaluated by comparing actual noise emission values, as detailed in Annex B, against similar machines within the same category Key contributors to sound generation include motors and moving components.
A noise emission declaration shall be given according to Annex B.
Protection against dust emission
Dust emission shall be minimized
For the machinery, this shall be achieved by one or both of the following methods:
an interface for connection to an aspiration system.
Ergonomic requirements
The design of the machine shall comply with EN 614-1
In particular correct positions of the body during cleaning and maintenance of the machinery shall be ensured, as well as during the replacement of parts
The manufacturer shall define procedures for the handling of heavy machine parts
Manufacturers must establish suitable methods for transporting machine parts weighing over 25 kg, ensuring compatibility with standard lifting gear or handling equipment, or provide the necessary handling equipment themselves.
Protective measures against hazards due to neglecting hygienic principles
Machinery of this European Standard shall be designed and manufactured according to EN 1672-2 and Annex
The 3 zones defined in EN 1672-2 are the following:
All the surfaces in contact with raw or processed materials (flour, semolina etc.) are considered food area
Key non food area food area
9 surfaces close to the feed zone
10, 11 surfaces close to the grinding rolls
12 surfaces close to brushes / scrapers
5.7.2.2 Plan sifter and rotary separator (see Figure 14)
Key non food area food area
5.7.2.3 Air classifier (purifier) (see Figure 15)
Key non food area food area
5.7.2.4 Air classifier (aspirator) (see Figure 16)
Key non food area food area
Figure 16 5.7.2.5 Rotating machine (see Figure 17)
Key non food area food area
5.7.2.6 Impact machine (impactor) (see Figure 18)
Key non food area food area
5.7.2.7 Impact machine (infestation destroyer) (see Figure 19)
Key non food area food area
Not present in these machines
All parts not mentioned in 5.7.2.
Measures against fire and explosion hazards
The machines shall be designed and constructed in accordance with the requirements of EN 13478
The machines shall be designed and constructed in accordance with the principles and requirements of
measures for avoiding or reducing potentially explosive atmospheres;
measures against potential ignition sources (static electricity, mechanical sparks, overheating of moving parts,…);
measures to reduce explosion effects
Machines should be engineered to reduce dust emissions, with one effective solution being operation at sub-atmospheric pressure The manufacturer must specify the necessary minimum under-pressure and include this information in the user guidelines.
If relevant the manufacturer shall indicate in the information for use the minimum humidity degree of the product
NOTE The informative Annex C, intended for the user of grain processing machines, gives information about the approach of the explosion hazards in plants including such equipment.
Harmful substance (cleaning and disinfecting agents)
The manufacturer shall give the necessary information on cleaning and disinfecting methods in the instruction for use
5.10 !! Safety related parts of control system
The safety related parts of the control system shall present a performance level defined in accordance with
EN ISO 13849-1:2006 with a minimum of level "c"."
6 Verification of the safety requirements and/or measures
This clause contains the methods for verification of the conformity of the machine with the requirements of Clauses 5 and 7
Verification shall comply with table 2 to 6
Table 2 — Roller mill Clause Method of verification
5.2.2.2 By visual inspection and by measurement of distance
5.2.2.3 By visual inspection or by measurement of distance
5.3 !Verification shall be carried out in accordance with Clause 18 of EN 60204-1:2006" 5.4 Measurement and declaration of noise emission values according to Annex B 5.5 Design verification
5.8 In accordance with EN 13478 and EN 1127-1
Table 3 — Plansifter Clause Method of verification
5.2.3.3 By visual inspection and checking the effectiveness of the adopted device
5.3 !Verification shall be carried out in accordance with Clause 18 of EN 60204-1:2006" 5.4 Measurement and declaration of noise emission values according to Annex B 5.5 Design verification
5.8 In accordance with EN 13478 and EN 1127-1
Table 4 — Air classifier Clause Method of verification
5.2.4.1 – 5.24.2 By comparing if time is in accordance with Instruction for use
5.3 !Verification shall be carried out in accordance with Clause 18 of EN 60204-1:2006"
5.4 Measurement and declaration of noise emission values according to Annex B
5.8 In accordance with EN 13478 and EN 1127-1
Table 5 — Rotating machine Clause Method of verification
5.2.6.1 - 5.2.6.2 By visual inspection and by measurement of distance
5.3 !Verification shall be carried out in accordance with Clause 18 of EN 60204-1:2006"
5.4 Measurement and declaration of noise emission values according to Annex B
5.8 In accordance with EN 13478 and EN 1127-1
Table 6 — Impact machine Clause Method of verification
5.3 !Verification shall be carried out in accordance with Clause 18 of EN 60204-1:2006"
5.4 Measurement and declaration of noise emission values according to Annex B
5.8 In accordance with EN 13478 and EN 1127-1
General
Information for use shall be provided according to Clause 6 of EN ISO 12100-2:2003 and with additional information as required in the following subclauses.
Safety signals and warning devices
Manufacturers must address residual risks through the use of safety signs when technical measures or design cannot sufficiently reduce certain risks.
Instruction handbook
The instruction handbook must adhere to section 6.5 of EN ISO 12100-2:2003, providing a comprehensive overview of the machine's operation along with essential guidelines for safe handling, storage, installation, startup, shutdown, and maintenance.
The description of the machine shall include the most important technical data (dimensions, weight, installed power, speed of rotating and stroking components, product rate)
For the machine characterized by rotating or stroking motion (see 3.2 and 3.3) shall be specified the value of stroke or of eccentricity during the normal running
The description shall include figures showing the general working of the machine
The instruction handbook shall contain the documentation related to the electrical equipment
The handbook must provide clear instructions for properly executing setting operations when the machine is equipped with a keyboard or display for input and data display, along with visual representations of the displayed data.
If relevant the manufacturer shall indicate in the information for use the minimum humidity degree of the product
!The instruction handbook shall give the following declared noise emission values determined in accordance with Annex B
the A-weighted emission sound pressure level at the workstation, where this exceeds 70 dB; where this level does not exceed 70 dB, this fact shall be indicated;
the A-weighted sound power level of the machinery where the A-weighted emission sound pressure level at the workstation exceeds 80 dB."
The instruction handbook must detail the technical specifications of the equipment used for operating the machine, including the minimum capacity requirements for ropes, hooks, and hoists Additionally, it should provide illustrations demonstrating the proper methods for securing this equipment to the machine.
The instruction for use shall give the conditions for storage (e.g dry and cover place)
The information for installation shall include where relevant, with illustrations if necessary, the following specific elements:
required civil works (e.g supporting structures, floor holes), and the expected floor load;
To ensure safe maintenance operations, it is essential to maintain a minimum free space around the machine, which includes the area between the machine and walls, as well as the space between the machine and other equipment.
The placement of anchor points and the selection of anchoring equipment, such as bolts, screws, or rawlplugs, are crucial It is essential to consider the characteristics of this equipment, including property class, diameter, and length, as well as the forces to be applied, particularly the tightening torque.
When assembling the machine with other equipment, it is essential to adhere to specific principles, such as ensuring that access to moving parts at connection points is restricted (refer to section 5.2.1) and implementing measures to prevent static electricity (see section 5.3.5).
where relevant, the specifications for connection to an exhaust system (see 5.5 and 5.8.2)
Required actions for start up and stop of machine and the correct sequence of operations shall be described
It shall be stated that these actions require technical knowledge and shall be carried out exclusively by trained people (see 7.3.8)
To ensure safety during maintenance interventions, it is essential to follow the guidelines outlined in section 5.5.4 of EN ISO 12100-2:2003 This includes disconnecting all energy supplies, implementing measures to prevent reconnection, neutralizing any residual energy, and verifying that the equipment is in a safe state.
NOTE Depending on the case these instructions can be for the individual machine and/or for the integration of the machine in a plant
It shall be stated that the maintenance operations have to be carried out by trained people (see 7.3.8)
If the maintenance actions require the removal of fixed guards, it shall be specified that these protections shall be correct repositioned and fast re-fixed before running the machine
The force or the tightening torque to be applied at fixing points of fixed guards and of rotating or stroking components shall be specified
It is suggested that instruction handbook include a systematic description of the fixed guards of the machine
!The specification of the spare parts to be used, at least when these affect the health and safety of operators."
Operators must receive training on the hazards of machine use and the necessary safety precautions The instruction handbook will provide detailed information outlining the essential training components required for safe operation.
NOTE It is recommended that operating personnel should be instructed during installation by a representative of the manufacturer or the supplier of the machine.
Marking
EN ISO 12100-2:2003, Clause 6 shall apply with the following information on the identification plate of the machine:
!the business name and full address of the manufacturer and, where applicable, his authorised representative;"
electric, pneumatic and water ratings;
!year of construction, that is the year in which the manufacturing process is completed."
2) For machines and their related products intended to be put on the market in the EEA, CE marking as defined in the applicable European directive(s) E.g Machinery
Principles of design to ensure the cleanability of machinery
For the purposes of this annex, the following terms and definitions apply
A.1.1 easily cleanable designed and constructed to permit the elimination of soil by simple cleaning methods (e.g hand and sponge cleaning)
A.1.2 fitted surfaces surfaces are fitted when the distance separating them is less than or equal to 0,5 mm
A.1.3 joined surfaces surfaces are joined so that no particle of product becomes trapped in small crevices, thus becoming difficult to dislodge and so introduce a contamination hazard
The materials in contact with foods shall be compatible with this foods 3)
Generally the most widely used material is stainless steel, grade X5CrNi18-10 (1.4301) EN 10088-1, grade X5CrNiMO17-12-2 (1.4401) EN 10088-1 or grade X2CrNiMO17-12-2 (1.4404) EN 10088-1 (austenitic microstructure);
Some materials (e g plastics) may be the subject of overall or specific migration tests
Cleanability is an important factor in selecting the proper plastic material (i e polypropylene PP, polyvinyl chloride unplasticised PVC, acetal copolymer, polycarbonate PC, high density polyethylene HDPE)
The use of polytetrafluoroethylene (PTFE) requires particular careful application, because:
PTFE is difficult to clean,
PTFE gaskets are not permanently impermeable to micro-organisms
3) European Directives give lists of compatible materials Materials not mentioned in the European Directives are accepted as long as food compatibility is proven
The design must ensure that lubricants do not come into contact with food, or it should consider the use of compatible lubricants, such as those based on paraffinic oils, polyalphaolefins, or silicone thickened with aluminum or calcium complex soaps.
A.2.1.2 Materials for non-food area
The surface finish of materials must allow for easy cleaning under acceptable conditions Additionally, the roughness values (Rz) must adhere to the specifications outlined in ISO 468 and conform to the values provided in tables A.1 and A.2.
A.2.2.1 Surface conditions for food area
Technique of construction Roughness (Rz)
Connections shall have the same roughness as the connected surfaces These should be designed to avoid any dead space, see !EN 1672-2:2005"
A.3.1.2 Connections of internal surfaces for food area
Two surfaces shall be connected according to:
a rounded edge having a radius (r 1) greater or equal to 3 mm obtained:
4) ISO 468 is now replaced with ISO 4287 and 4288 The corresponding modification of this document is under study
by machining (cutting into material mass);
or by bending the sheet metal (bending and forming);
or by the design (in moulds, shells of foundry, injection and blasting ) (see Figure A.1);
or by welded assembly with grinding and polishing (see Figure A.2);
for an internal angle (α1) equal to or greater than 135° there are no special requirements for the radius (see Figure A.3)
When using rounded edges, ensure that two edges have a radius of at least 30 mm, while the third edge should have a radius of at least 7 mm Additionally, maintain an angle of 135°, ensuring that the dimension (l₁) between the two bends is equal to or greater than 7 mm, as illustrated in Figure A.4.
Figure A.4 A.3.1.3 Connections of internal surfaces for non-food area
The sheet metal assembly methods shall take into account the expansion or shrinkage phenomena due to temperature variations
A.3.2.2 Surface assemblies and overlaps for food area
Assembled surfaces are considered joined either:
by a continuous weld (see Figure A.5);
a continuous sealed and flushed joint (see Figure A.6)
In cases where mandatory technical constraints exist, such as with long sheet metal parts of varying thicknesses, assemblies can be created by overlapping sheets, ensuring that the joined surfaces are securely connected.
either by a continuous weld or
the upper surfaces shall overlap the lower surfaces in the direction of liquid flow (see Figure A.7)
Connections must adhere to the guidelines for rounded areas in food zones, ensuring continuous sealed and flushed jointing if construction is not feasible.
When the combined thickness of the overlapping section and joint exceeds 1 mm, the upper part must be chamfered to reduce the thickness (d) to 1 mm or less, as illustrated in Figure A.4.
A.3.2.3 Surface assemblies and overlaps for non-food area
If construction requires the use of hexagon socket head screws embedded in a spot face:
either production shall comply with the Figure A.10 and the manufacturer in his instruction handbook can prescribe suitable cleaning facilities (e.g high pressure jet)
or the manufacturer shall take the necessary steps to fill in the spot face by sealed and lasting plugs corresponding to the requirements of the food area
Pin drive systems must be solid and assembled as flush as possible Manufacturers are allowed to implement an inspection procedure to verify adherence to this requirement.
A.3.3.2 Fasteners for non-food area
A.3.4.1 Fixed machines with of without a base
Fixed machines must be securely anchored to the floor using a continuous and sealed joint, as specified in the instruction handbook (refer to Figure A.11), or they should have feet (H) that are at least 150 mm in height.
However, if the space (L) to be cleaned is not deeper than L = 150 mm, the height H can be reduced to
100 mm as long as the various access possibilities are taken into account (see Figure A.12)
If the foot surface is greater than 1 dm 2 , the feet shall be considered to be a base (with interposed seal) (see Figure A.13)
The castors shall be cleanable An example is given in Figure A.14, where b is the greater width of covering at the circumference of the wheel
Figure A.14 A.3.5 Ventilation openings for non-food area
Ventilation openings shall be in the non-food area
The direction of any fluid flow shall prevent any infiltration or retention in the machine
To prevent rodent access in technical areas of machines, it is essential to install guards that limit openings to a maximum dimension of 5 m.
Whenever possible, the manufacturer shall eliminate swivel points from the food area
If their presence in the food area is technically necessary, then:
they shall be easily removed;
if they cannot be removed, all surfaces should be accessible
Assemblies with a fixed component must utilize a joint specifically designed to prevent infiltration Access to these areas is permitted only when the passage width (\$l_3\$) is at least twice the depth (\$p\$) Additionally, the width (\$l_3\$) must not be less than 10 mm, as illustrated in Figure A.16.
Normally, the control panel shall be in the non-food area and cleanable whenever possible
Noise test code for grinding and processing flour and semolina (grade 2)
Definitions of noise related technical terms are given in EN ISO 12001
The appropriate test environment for measuring the emission sound pressure level must be a flat outdoor area, such as a parking lot, or an indoor space that offers a nearly free field over a reflecting plane This environment must comply with the specifications outlined in Annex A.
To accurately assess the noise emission values of machinery, it is crucial to prevent electrical conduits, piping, or air ducts connected to the equipment from radiating excessive sound energy This can be achieved by implementing damping techniques or partially encasing these components.
During the determination of the emission sound pressure level and the sound power level, the operating conditions shall be as follows:
the machine shall be empty;
it shall operate at its maximum speed
B.4 Emission sound pressure level determination
The determination of the A-weighted emission sound pressure level shall be done in accordance with
The measurement time for sound pressure level measurements for the determination of the emission sound pressure level shall be 30 s
Measurement for grinding and processing flour and semolina will be conducted on each side of the machine, without the presence of an operator, due to the absence of designated workstations.
The measurement shall be made at 4 microphone positions at:
a height of 1,55 m ± 0,075 m above the floor;
1,00 m ± 0,02 m away from each side of the reference box defined in EN ISO 3744
The value of the highest emission sound pressure level shall be used for declaration
The background noise, measured using A-weighting or specific frequency bands, must be at least 6 dB lower than the noise level produced by the machine being tested, with a preference for a difference greater than 15 dB.
To accurately measure the emission sound pressure level at a designated location, it is essential to apply the background noise correction factor K1 The calculation and application of K1 must adhere to the guidelines set forth in EN ISO 11201.