We would like to clarify what is dust, the rating of Dust Masks and clear up what is happening in the market.
Dust masks in South Africa come under the National Regulator of Compulsory Standards (NRCS) and a Homologation Certificate from SABS or NRCS certifying that the masks meet SANS 10338:2009 Standard. Masks supplied to mines in Botswana must be registered with the Botswana Department of Mines who will require a Homologation Certificate.
Southern Africa Follows the European Standards so the masks sold in Southern Africa will be rated FFP1, FFP2 and FFP3. Normally we do not see the N95 or KN95 masks, but due to the world shortage caused by the Corona Virus, these have been allowed in. The N95 and KN95 are similar standard to the FFP2 Masks. There are many fake masks in the market that do not meet any standards but have been marked KN95. See my separate posting on spotting a fake mask.
OEL – Occupation Exposure Limit is the “Safety” line. If any one of the hazards are above the OEL then action is required
APF – Assigned Protection Factor will determine the rating of the mask required. If the actual concentration of dust is 300ppm and the OEL is 100ppm then the APF would be calculated as follows: 300/100 = 3. Therefore an FFP1 Mask with and APF of 4 will be adequate.
FFP1 Assigned Protection Factor APF = 4
FFP2 Assigned Protection Factor APF= 10
FFP3 Assigned Protection Factor APF= 30
Particle Sizes are defined that particles smaller than 5 micrometers (millionths of a meter) are classified as dusts, between 2 and 5 micrometers are classified as fine particles and less than 2 micrometers are very fine.
Oxygen levels where respiratory equipment should be used is where the oxygen levels in the atmosphere exceeds 17%. Do not use dust masks, half masks and full face masks where the oxygen level is below 17%. Oxygen levels below 17% indicate the presence of another gas which may be lethal.
Duration of use. Moulded dust masks are designed for one 8 hour shift according to the relevant OEL. If the concentration of contaminant is higher the mask should be replaced sooner. Increased breathing resistance will indicate that it is time to change the mask.
Life period tests indicate that a FFP2 mask will last varying times depending on the concentration of the contaminant.
0.05mg/min @ 45Pa is 26.7 hours
0.10mg/min @ 45Pa is 13.3 hours
0.15mg/min @ 45Pa is 8.3 hours
From this table you can see that the life of the mask is dependent on the concentration of the dust. The higher the concentration the shorter the life. In very low contamination areas the life will extend beyond one shift. The problem is how the mask is stored between shifts without contaminating the inside of the mask.
Levels of Protection
Silica causes silicosis and this may not be detected until later. Silica is found in granite. The minimum level of protection where granite is found is FFP2
Nickel is Carcinogenic (causes Cancer). The minimum Level of Protection on a Nickel Mine is FFP3.
Copper . The minimum Level of Protection on a Copper Mine is FFP2.
Cement . The minimum Level of Protection on a Cement plant is FFP2.
Coal dust . The minimum Level of Protection for coal dust is FFP2.
Quartz dust . The minimum Level of Protection for Quartz dust is FFP2.
Radioactive Particles . The minimum Level of Protection for radioactive dust is FFP3.
Foreign Owned Mines and Quarries. If the laws in the owner’s country stipulate the use of a higher level of protection then required locally, you must follow the laws of the owners country.
Note: If staff working in low dust areas insist on changing dust masks at every shift this will become a very expensive operation. The alternative is to change to a cheaper, less comfortable mask which still meets the standards.
If you are using an FFP1 dust mask on a mine or quarry, you are breaking the law and not only will the Mine, but every designated person will be personally liable for damages and may also be prosecuted. This includes the managers, foremen, SHE officers, materials management and buyers.
Your audited accounts should also disclose that you could be subject to a claim from previous employees for not providing correct safety equipment which has caused respiration problems.
You have been warned, use the correct dust masks in your application and be safe.