Crystalline silica is omnipresent in various activity fields such as construction, quarries, glassworks or even foundries. In the form of alveolar dust, if inhaled it represents a real danger to workers’ health. Our experts will show you the characteristics of this harmful dust and the respiratory protection equipment to use.
The dangers of silica
What is crystalline silica?
Silica is an element present in a large number of minerals in different forms, in particular crystalline or amorphous. Its pure form crystallizes under different temperatures and pressure conditions. Among them: quartz, tridymite and cristobalite.
Crystalline silica is a ubiquitous element in the earth's crust. Indeed, it is also found in many mineral origin construction materials such as sand, granite, concrete, stone, etc. With a less than 5 micrometers (microns) size, respirable alveolar dust (defined by its ability to reach the pulmonary alveoli) from crystalline silica is generated by many professional activities. It represents a real health hazard when inhaled.
Health effects
Crystalline silica is classified as a known human carcinogen (group 1). Exposure to this type of dust and its inhalation can cause many health problems:
- skin irritations
- eye inflammation
- bronchitis
- emphysema
- tuberculosis
- immune system damage
- autoimmune diseases
- lung cancer
- silicosis
Potentially lethal, the dangerousness of this substance for the body implies taking safety measures for all exposed persons.
Exposure situations
Exposure to crystalline silica dust is an omnipresent risk in a large number of activity fields, particularly on construction sites and in certain workshops. In France only, the ANSES (French National Agency for Food, Environmental and Occupational Health Safety) estimates that nearly 365,000 workers are affected by exposure to this element in their professional activity.
Professional fields concerned by the crystalline silica risk:
- Construction / Building works
- Stone cutting
- Cement production & use
- Ceramic and porcelain production
- Glassworks
- Dental prostheses production
- Foundry
- Plastic production
- Mines and quarries
Silica: regulation and prevention
Regulations
The dangers induced by the presence of crystalline silica in many professional activities lead to strict regulations. In France and in Europe, exposure to this substance is limited by law to specific levels.
| Occupational exposure limit value over 8 hours | |
| Crystalline silica: | OEL mg/m3 |
| alveolar quartz dust | 0,1 mg/m3 |
| alveolar cristobalite dust | 0,05 mg/m3 |
| alveolar tridymite dust | 0,05 mg/m3 |
Moreover, since 1997 crystalline silica has been classified as a carcinogen by the IARC (WHO International Agency for Research on Cancer). This classification and its recognition by the various national authorities entail specific regulatory obligations for CMR agents (carcinogenic, mutagenic or reprotoxic) for employers.
Silica danger prevention
Faced with the dangers of crystalline silica and the regulations in force, prevention plays a key role in the various applications exposed to this type of respirable dust. Many arrangements can be made to minimize the generation of this dust in work environments. Among these means of collective protection and security measures, we note:
- wet work
- workstations isolation
- use of dust extraction booths
- mechanization of hazardous tasks
- risk assessment
- working atmosphere control
- reinforced monitoring of exposed workers
- complete cleaning of exposed areas
- use of PPE (personal protective equipment)
- proper maintenance of the used PPE
Finally, in addition to these preventive measures, like asbestos respiratory protection, concerned people (employees, workers) must systematically be informed of the risks incurred in presence of crystalline silica.
Silica protective equipment
Crystalline silica exposure prevention methods should be accompanied by personal protective equipment. The use of a respiratory protection mask as well as wearing an dust suit ensures minimal exposure to the hazard.
The silica respiratory protection mask
In addition to the various prevention measures, wearing a respiratory protection mask specially adapted for fine particles is essential to ensure workers’ safety when exposed to crystalline silica.
The GVS Elipse mask
Today there are few dust masks able to filter ultra fine particles. In fact, most gas mask filter manufacturers offer equipment that filters particles in the 1 to 0.6 microns range. Respirable crystalline silica dust with a less than 5 microns diameter, with particles up to 0.3 µm regularly present, is therefore not filtered by these protective devices. Exposure to this type of particles requires the use of very high performance filters.
For this purpose, our experts recommend the use of the GVS Elipse mask with its P3 filters.
This respiratory protection mask is ergonomic, easy to use, very comfortable to wear and has high precision filters. GVS mask technology deploys a HESPA® (High Efficiency Synthetic Particulate Airfilter) multi-layer pleated filter. These P3 filters have a minimum efficiency of 99.95% or more for 0.3 micron particles. They have a 40 Nominal Protection Factor (PNF) (reducing the dust concentration between the outside and inside of the mask by 40). These filters are effective up to a maximum concentration of 50 times the OEL. All these properties make this mask ideal for protection against alveolar crystalline silica dust.
Powered air purifying respirators for long-term work
For operators working in contact with silica over long periods of time, we recommend using powered air-purifying respirators, the most effective form of filtering respiratory protection.
The CleanSpace Pro is an ALL-IN-ONE powered air purifying respirator. With no cables and a motor block located at the nape of the neck, the user is protected against fine particles, and he takes advantage of complete freedom of movement. It is totally suitable for the construction industry or quarries, where workers spend long hours in contact with silica dust. Innovative, it adapts its airflow to the user's breathing and has 14-hour autonomy.
The PureFlo 3000 powered air purifying helmet has an integrated motor and filter inside. It covers the entire respiratory tract, head, and face. Cable-free, it offers the user ease of use whatever the duration of the operation. Equipped with a HEPA filter, the PureFlo 3000 effectively protects against aerosols and tiny particles such as lead or crystalline silica. Therefore it is suitable for the construction, cement, and sandblasting industries.
The dust protective suit
To maximize protection against crystalline silica particles, wearing a dust suit is also recommended. This type of PPE, a protective suit or HAZMAT suit, provides a barrier against respirable dust exposure. This reusable or disposable protection should be used to prevent contamination by particles and their transport outside the workplace.
Our team of experts recommends wearing an NS Series suit when silica dust is present. This type 5 & 6 disposable personal protective equipment offers category 3 protection against liquid splashes and dust. Ergonomically designed, it offers comfort and prevents penetration of substances, thanks to retractable sleeves, 2-piece diamond leggings, and elasticated tightening. Suitable for the cement and mining industries.
Another protective suit is equally effective in combating fine dust particles, making it suitable for workers who come into contact with crystalline silica. The TS series microporous combination contains an adhesive tape seal to prevent dust penetration. It is made of polyethylene and fits snugly around the body, offering comfort and ease of movement when working with silica. Stonemasons and construction workers might find it perfect for their applications.
GazDetect is at your disposal for the selection of your chemical suits and respiratory protection equipment. Do not hesitate to contact us for information or to request a quote.