Silicosis claims: an overview

Published: 10/01/2024 | News

As stated by the Health and Safety Executive[1]:

“Silica is a natural substance found in varying amounts in most rocks, sand and clay.  Silica is also a major constituent of construction materials such as bricks, tiles, concrete and mortar.  Dust is generated from these materials when cutting, drilling, grinding and polishing.  Heavy and prolonged exposure to silica can cause lung cancer and other serious respiratory diseases. Silicosis usually follows exposure to silica dust over many years, but extremely high exposures can cause acute silicosis more quickly.”



As per section 11(4) of the Limitation Act 1980, it provides that the action shall not be brought after the expiration of three years from (a) the date on which the cause of action occurred; or (b) the date of knowledge (if later) of the person injured.  If the claim is not issued within the limitation period, then the Claimant will be required to rely upon section 33 of the Limitation Act 1980.  Silicosis claims are likely to have latent damage occurring sometime after exposure and potentially with a slow, insidious onset, therefore, the application of section 14, and determining the Claimant’s date of knowledge, is fundamental in these types of cases.

The Supreme Court (by a 4:3 majority) in MoD v AB and Others [2012] UKSC 9, paragraph 11, held that a Claimant was likely to have acquired knowledge of the facts specified in section 14(1) of the Limitation Act 1980 when he first came reasonably to believe them.  Lord Mance clarified this at paragraph 82 and stated:

“The speeches in the House of Lords endorsed guidance regarding the concept of knowledge given in a series of Court of Appeal decisions, going back to Halford v Brookes [1991] 1 WLR 428.  Lord Nicholls said at paragraph 9: “Thus, as to the degree of certainty required, Lord Donaldson of Lymington MR gave valuable guidance in Halford v Brookes [1991] 1 WLR 428, 443.  He noted that knowledge does not mean knowing for certain and beyond possibility of contradiction.  It means knowing with sufficient confidence to justify embarking on the preliminaries to the issue of a writ, such as submitting a claim to the proposed defendant, taking advice, and collecting evidence: ‘suspicion, particularly if it is value and supported, will indeed not be enough, but reasonable belief will normally suffice.’  In other words, the claimant must know enough for it to be reasonable to begin to investigate further.”

It was confirmed by Lord Wilson at paragraph 13: “In my view the date upon which the claimant first consulted an expert is not, on its own, likely to assist the court in determining whether by then he had the requisite knowledge… In my view, however, it is a legal impossibility for a claimant to lack knowledge of attributability for the purpose of section 14(1) at a time after the date of issue of his claim.”

Determining the Claimant’s date of knowledge is key when considering whether the claim is within the limitation period.  The case of MoD v AB and Others [2012] UKSC 9 provides some helpful factors in relation to the Claimant’s actions when assessing their date of knowledge, but the court will assess it on a case by case basis.


Duty of Care

The duty of care that any potential Defendant may owe the Claimant will depend upon the Claimant’s working status, as with any employers’ liability claim.  The duty is to take reasonable care to protect those affected by an activity against a foreseeable risk of injury to their health.

If the Claimant is an employee of the Defendant, then the Defendant will owe them a common duty of care as well as the various duties under the relevant Regulations that were in force during the Claimant’s employment.


Breach of Duty of Care

In order to determine whether the Defendant has breached their duty of care, the court will be required to consider expert evidence from either an engineer or industrial hygienist who will provide evidence on the level of exposure or likely level of exposure experienced by the Claimant.  The level of exposure that the Regulations permit will be dependent on when the Claimant was exposed to silica dust.  The Court of Appeal held in Jeromson v Shell Tankers UK Ltd [2001] EWCA Civ 101 that the Defendants should have taken into account the extent of the exposure to which an employee was potentially subjected to, rather than that to which he was actually subjected when considering whether the Defendants were in breach of the duty of care.  Lady Justice Hale further clarified the position at paragraph 37:

“However, where an employer cannot know the extent of any particular employee’s exposure over the period of his employment, knows or ought to know that exposure is variable, and knows or ought to know the potential maximum as well as the potential minimum, a reasonable and prudent employer, taking positive thought for the safety of his workers, would have to take thought for the risks involved in the potential maximum exposure.  Only if he could be reassured that none of these employees would be sufficiently exposed to be at risk could he safely ignore it.”

Regulation 2(1)(d) of The Control of Substances Hazardous to Health Regulations 2002 (2002 Regulations) sets out the general definition for “substance hazardous to health”:

 “Dust of any kind, except dust which is a substance within paragraph (a) and (b) above, when present at a concentration in air equal to or greater than-

(i) 10 mg/m3, as a time weighted average over an 8-hour period of inhalable dust, or

(ii) 4 mg/m3, as a time weighted average over an 8-hour period of respirable dust.”

Regulation 2(1) sets out that “Inhalable dust” means airborne material which is capable of entering the nose and mouth during breathing; and “Respirable dust” means airborne material which is capable of penetrating to the gas exchange area of the lung.

But as highlighted in the case of Harry Mills v JP Barnes & Sons Ltd (Tuesday 25 June 2013, Leeds County Court) at paragraph 5:

“The limit has had different names and has been set at different levels, presumably in the light of developing medical knowledge over the years, so that the threshold limit value of silica at the start of the Claimant’s employment was 0.1 mg/m3. When the COSHH Regulations first came into force in 1989 silica was assigned an occupational exposed standard of the same figure.  In 1992 the maximum exposure limit was set at 0.4 mg/m3, but the duty was to reduce exposure to as low as was reasonably practicable.  That limit changed to 0.3 mg/m3 in the 1990s.  In 2006 the limit was changed to a workplace exposure limit, but to the original figure, 0.1 mg/m3.”


Once a Claimant has established that he was exposed to a substance hazardous to health and sustained injury as a result, the burden in proving compliance with the Regulations is upon the Defendant.

Under Regulation 6 of the 2002 Regulations the employer comes under a duty to its employees whenever the work is liable to exposure of any employees to any substance hazardous to health.  It requires an employer to have made a suitable and sufficient assessment of the risk created by that work to the health of those employees and the steps that need to be taken to meet the requirements of the Regulations, and also implemented the steps that have been identified.

Regulation 7 of the 2002 Regulations imposes first a duty to prevent exposure.  Then only if the exposure cannot be prevented, so far as is reasonably practicable, should the employer implement control measures.


The Health and Safety Executive website[2] sets out a number of steps an employer can take in order to control the risks of exposure, once a risk assessment has been carried out and identified which harmful substances are present and how employees can be harmed:

  • elimination: does a particular substance need to be used? Is there a safer alternative?
  • changing the process to reduce risks: can the process be changed to reduce the risk of exposure?
  • containment: enclose the process or activity as much as possible to minimise the escape or release of the harmful substance. Use a properly designed local exhaust ventilation (LEV) system which extracts dust, fume, mist, gases or vapour through a hood or booth and reduces the exposure of the employee.
  • systems of work: restrict access to those people who need to be there.
  • cleaning: exposure can occur during cleaning so plan and organise the workplace so that it can be easily and effectively cleaned.
  • personal protective equipment (PPE): if exposure cannot be adequately controlled by other means, then provide PPE in combination with other control measures.
  • information and training: provide employees with information about hazards and risks, workplace exposure limits, and what they need to do to protect themselves. Employees must be made aware of results of any monitoring of exposure and the collective results of health surveillance.
  • record your findings: make a list of the actions you have taken to control the risks to the employee’s health.
  • review your controls: periodically review the measures and controls in place.

Once a control measure is provided, as per Regulation 8(1) of the 2002 Regulations, the employer must ensure that it is properly used or applied.  Regulation 9 provides that any equipment is maintained, for example, the LEV system.  The employer must monitor exposure at the workplace where indicated by the risk assessment or otherwise appropriate, as per Reulgation 10 and Schedule 5 of the 2002 Regulations, and also maintain health surveillance over the employees, as per Reulgation 11 and Schedule 6 of the 2002 Regulations.  Furthermore, Regulation 12 of the 2002 Regulations provides that there is a duty to provide employees with suitable and sufficient information, instruction and training.

In order to establish whether the Defendant has breached their duty of care, it is important that the Claimant’s period of exposure, the relevant Regulations in place at the time, including the applicable exposure limits are correctly identified.  The Defendant’s disclosure will usually contain the risk assessment, training, and information and PPE and other control measures the Defendant put into place in order to prevent or limit the exposure of the Claimant to silica dust.



The Claimant will require medical evidence to establish that an injury was sustained and that it was caused by the breach of duty.  Provided that some injury is foreseeable, it does not matter if the particular injury sustained was not foreseeable; this is the position even if the disease was unknown at the time of the alleged breach of duty.

The issue with silicosis is whether the Claimant’s condition is compensatable?  There are two questions that the court needs to consider, first, is the Claimant’s condition symptomless, and secondly if so, can Rothwell, Grieves v Everards and Others [2007] UKHL 39 be distinguished?  In Rothwell, the House of Lords were dealing with an asbestos-related condition known as pleural plaques.  Lord Hoffman described pleural plaques as areas of fibrous thickening of the pleural membrane which surrounds the lungs.  It could be argued that silicosis is similar to pleural plaques in that, neither condition, being symptomless, of itself necessarily leads to any further inquiry and neither are therefore actionable.  However, Lord Hope in Rothwell considered the House of Lords case of Cartledge v Jopling [1963] AC 758 at paragraph 37, and stated:

“The first question is what we mean when we refer in this context to injury.  In Cartledge v Jopling Lord Pearce said that there was no case that had sought to define the borders of actionable injury.  The issue in that case was whether an injury which had been sustained before the claimant knew that he had been injured could nevertheless be said to be actionable.  As Lord Pearce explained, it was impossible to hold that a person who has no knowledge of the secret onset of pneumoconiosis and suffers no present inconvenience from it cannot have suffered any actionable harm, but the evidence in that case was that a person who is susceptible to pneumoconiosis and who inhales the noxious dust over a period of years will have suffered substantial injury to his lungs before his injury can be discovered. … There must be real damage as distinct from damage which is purely minimal.  Where that element is lacking, as it plainly is in the case of pleural plaques, the physical change which they represent is not by itself actionable.”

As stated in Harry Mills v JP Barnes & Sons Ltd (Tuesday 25 June 2013, Leeds County Court) at paragraph 22:

“The House of Lords in Rothwell clearly had the opportunity to hold that Cartledge was no longer good law.  They did not do so. This must be because, like other insidious conditions, silicosis even in its simple form is not to be equated with symptomless pleural plaques.”

However, it should be noted that Harry Mills v JP Barnes & Sons Ltd is not a binding authority, and a court may make a different finding in relation to the application of these authorities depending on the medical evidence in a particular case.

Benign lung function consequences in the form of respiratory restrictions with scarring to the lung must be an injury since it damages the tissue rather than just pleural plaques.  But this can be contrasted with cancer cases and cases with a future risk of cancer where the court may award provisional damages under Part 41A of the Civil Procedure Rules.  The case of Jones v Secretary of State for Energy and Climate Change (The Phurnacite Workers Group Litigation) [2012] EWHC 2936 in which the operators of a phurnacite plant had breached multiple statutory duties owed to their employees over a period of 50 years.  The breaches of duty covered both the COSHH Regulations and the preceding Factories Act 1937 and 1961.  As cancer is caused by exposure over several decades prior to the cancer developing, the enactment of the COSHH Regulations in October 1989 is probably too late to be of causative relevance for many cancers developing now.  Novartis Grimsby Ltd v Cookson [2007] EWCA Civ 1261 dealt with negligence and breach of the Factories Act 1961.  The COSHH Regulations are applicable to exposure between 1989 and 2013 after which claims will revert to negligence.

A provisional damages award is made on the provisional basis that the Claimant’s condition will not deteriorate in the future in some identified and rather severe way.  A provisional lump sum will compensate the Claimant for the past and for the future loss on that assumption.  If the Claimant does suffer a triggering disease or deterioration the original order allows the Claimant to return to court for further damages to cover the additional suffering and loss.  The Claimant is required to prove that at some definite or indefinite time in the future they will, as a result of the act or omission which gave rise to the cause of action, develop some serious disease or suffer some serious deterioration in their physical or mental condition.  There are four grounds to any such application:

(a)        the claimant has suffered personal injuries; and

(b)       the claimant faces a chance or risk of

(c)        developing a serious disease or deterioration in his conditions; and

(d)       the discretion should be exercised.

The level of risk necessary for the court to make an award for provisional damages has been considered in a number of cases and it is clear that so long as the risk is not de minimis the court may make such an award.

As to the issues that may be relevant to a claim for silicosis, it will depend on the facts and evidence of that particular case.  The number of reported cases in relation to silicosis is currently limited, however, there is expected to be an increase of such claims in the future, thus providing further guidance on the relevant legal principles.




Article by Dr Lindsey Hogg who is developing a specialist practice in industrial disease and who welcomes instructions from either claimants or defendants.