Frequently Asked Questions
Questions & Answers are grouped in the following categories. Click on a link or scroll down to go to the section:
Legislation & Standards
For more information and advice, please contact the Helpline:
3M Health & Safety Helpline
0870 60 800 60
1 800 320 500
Monday - Friday: 9.00am to 5.00pm
For further information please contact us.
I’ve been told to look on the “MSDS” for some information. What is it and where do I get one?
The MSDS or Material Safety Data Sheet is a document published by the manufacturer/processor of a substance that includes information on its usage and handling.
This may include toxicological effects, level of flammability and a breakdown of compounds. Manufacturers are obliged by law to provide a MSDS.
When should I carry out a risk assessment?
The simple answer to this question is that you should carry out an assessment when you suspect that there is a risk.
The assessment needs to be of the risks created by the work, not the substances.
It is a mistake to think that a risk assessment need only consist of a collection of manufacturers health and safety data sheets. This is often caused by a failure to understand the difference between a hazard and a risk.
Hazard - The potential to cause harm.
Risk - The likelihood that the harm will occur in practice.
A good analogy is a bottle of household bleach. The hazard is the bleach itself, but there is very little risk when the bottle is in a cupboard, but that risk increases if the bottle is left on the edge of a work surface with the lid off.
There is a raft of legislation relating to risk assessment including:
Section 2. Health & Safety at Work Act 1974, General Duties of Employers Employers are required to ensure, so far is reasonably practicable, the health, safety and welfare of all his employees. This does not implicitly mean that you have to carry out a risk assessment, but it would be difficult to comply with the regulation without having assessed the risks.
Regulation 3. Management of Health & Safety at Work Act 1992. A more explicit set of regulations that require risk assessments to be carried out.
Regulation 6. Control of Substances Hazardous To Health Regulations (COSHH). An employer shall not carry on any work which is liable to expose any employees to any substance hazardous to health unless he has made a suitable and sufficient assessment of the risks created by that work to the health of those employees and of the steps that need to be taken to meet the requirements of these Regulations.
How does “Oxygen Deficiency” occur?
Oxygen Deficiency occurs when the percentage of oxygen in the air falls below 19.5% (a 3M definition). It can be caused by chemical reaction, fire or when other chemicals displace oxygen from the air. Typically this occurs in confined spaces where there is poor ventilation.
What is meant by “IDLH”?
This is the concentration considered Immediately Dangerous to Life or Health (IDLH) as defined by the NIOSH (in the USA). The IDLH concentration is defined as "that poses a threat of exposure to airborne contaminants when that exposure is likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such an environment."
The IDLH value represents a maximum hazard concentration from which a worker would escape within 30 minutes without any escape impairing symptoms or any irreversible health effects.
Legislation & Standards
What are “Occupational Exposure Limits”?
Occupational Exposure Limits (OEL) are guidelines to acceptable levels of exposure to various respiratory hazards. OELs are listed for many common substances in the HSE document EH40. OELs are expressed either as OESs or MELs.
- OES - Occupational Exposure Standard. Exposure to substances assigned an OES should be reduced to below that standard as soon as is reasonably practicable. An OES is the current level for a substance for which the majority of employees may be exposed for eight hours a day, five days a week, without adverse health effects.
- MEL - Maximum Exposure Limit. This is enforceable by law. It sets out the maximum concentration of an airborne substance averaged over a reference period. Employees must not, under any circumstances, be exposed to levels above the MEL .
Why are there APFs and NPFs?
A respirator’s Nominal Protection Factor (NPF) is the theoretical protection level based on laboratory measured performance data.
An Assigned Protection Factor (APF), as detailed in BS4275, is the level of respiratory protection that can realistically be achieved in the workplace by 95% of adequately trained and supervised wearers.
The APF should be used when selecting a respirator.
What is “BS4275”?
The British Standard BS4275 is a “Guide to implementing an effective respiratory protective device programme”.
In summary, this Standard states that a respirator should be issued as part of a full respiratory protection programme that covers ;
- Hazard control
- Risk assessment
- Selection of RPE
- Storage procedures
Workplace Protection Factor (WPF) studies indicate that protection levels in the workplace are often substantially different from the Nominal Protection Factors (NPF) observed in the laboratory.
The British Standards Institute (BSi) has included the WPF/APF data in BS4275. It is unlikely that the APF will be achieved in the workplace without implementing a full respiratory protection programme .
What does the “CE mark” mean?
The CE symbol printed on the product/ packaging that informs the market that the product meets the essential requirements of the European directives relating to PPE. It could be described as a ‘passport’ to sell products within the European Union.
The CE mark is not a quality mark and does not indicate the performance of the product .
The product should meet the requirements of a relevant European Standard, e.g. EN149:2001 FFP1. This marking indicates the performance category of the product.
Does a half mask with particulate filters give a higher APF than a similar specification disposable respirator?
Purely based on the protection factor, and not taking into account other factors such as user acceptability and cost effectiveness, there is no difference in APF between disposable particulate respirators and a half mask fitted with the same specification filters.
There is a difference between the APF associated with using the same filter on a half mask and a full face mask. e.g. P3 filters on a half mask give an APF of 20 but when the same filters are fitted to a full face mask the APF is 40.
How long does a disposable respirator last?
Disposable particulate respirators, tested to EN149:2001, are approved for single shift use. Their effective usage time depends on a number of factors:
- Level of contaminant
- Breathing rate
- Hygiene factors
These factors vary from one workplace to the next. For example: an operative working in a very hot, dusty environment may decide to change their respirator at the end of the morning rather than use the same one all day .
How long will my gas/vapour filters last?
The life expectancy of a filter will vary from one job to another and is influenced by a variety of factors including the exposure time and location of the job. As long as the hazard has good warning properties, i.e. smell or taste at lower levels than the OELs, a filter can be used until breakthrough occurs, however this should not be routinely relied on.
Does MDF (Medium Density Fibreboard) give off Formaldehyde when it is cut or routed?
The Health and Safety Executive (HSE) has concluded that machining of MDF is no more, or less, hazardous than working with other forms of wood. In short, formaldehyde is not considered to be a problem.
The HSE has previously suggested that an FFP2 respirator could be evaluated for cutting or routing MDF in ventilated workshops eg. 3M™ 8822 / 9322 Respirators. Alternatively, you could try the 3M™ Powered Air & Airfed Respirators which have the added advantage of providing eye protection & head protection, depending on the model chosen.
What respirator should I use to protect against vehicle exhaust?
There is no simple answer to this question as there will normally be Oxides of Carbon and Nitrogen in the mixture of exhaust gases which cannot be filtered out.
The only way to protect against all the contaminants in vehicle exhaust would be with either a supplied air system or self contained breathing apparatus (SCBA). This solution is often not practicable so a compromise solution has to be reached. One option is a 3M half mask fitted with 3M™ 2128 Filters. These filters will filter out fine particulates and offer relief from nuisance levels of acid gas and organic vapours in the exhaust.
Can I use organic vapour filters with isocyanate based compounds?
The levels at which isocyanate can be detected by smell or taste are considerably higher than the Maximum Exposure Limit (MEL) as set by the HSE. There would be no indication of smell/taste that 'breakthrough' had occurred until an exposure higher than the MEL.
The safe solution would be to use an air fed system which supplies breathable quality air to the wearer rather than filtering out airborne contaminants. The 3M™ Visionair or S-200 Air Fed Systems could be considered for this type of application .
What respirator do I need when painting ?
As there are so many different types of paint in common use it is very difficult to suggest one product for everything.
The main problems are vapours from the organic solvent carriers and particulates in the form of pigments and spray mist. In most cases brush or roller applying paint is less hazardous than spraying since a lesser amount of pigment and vapour will become airborne. We suggest the following filter selections for the more commonly occuring paint application groupings :
- Powder coating – particulate filters or supplied air, depending on levels of contaminant.
- Water based – particulate filters often combined with nuisance level organic vapour protection when low levels of solvent are present.
- Solvent based with good warning properties – organic vapour & particulate filters.
- 2-pack isocyanate based – a minimum of a supplied air visor .
For specific product selection, please contact the 3M Health & Safety Helpline .