Cement

Wet cement is highly alkaline. A serious burn or ulcer can develop quickly if it is trapped against the skin. In extreme cases these burns may need a skin graft or lead to amputation of a limb. Cement can also cause chemical burns to the eyes.

Cement also causes dermatitis. It can abrade the skin and cause irritant contact dermatitis, and it contains hexavalent chromium (chromate), which can cause allergic contact dermatitis through sensitisation. The risk of injury depends on the duration and level of exposure and on individual sensitivity. Cement powder is a respiratory irritant, and the dust produced by cutting or drilling dried concrete and mortar can cause more serious lung disease.

Workers who handle or mix cement powder, or use wet mortar and cement, are particularly at risk. Check for existing skin or allergy problems, since this work can make them worse.

Basic recommendations for handling and using cement safely:

• work in ways that minimise the amount of cement dust released
• wet-cut rather than dry-cut masonry products where possible
• mix dry cement in well-ventilated areas
• work upwind of dust sources
• use ready-mixed concrete instead of mixing on site, where possible
• avoid skin contact and unnecessary kneeling in wet cement; select suitable waterproof protection and methods that prevent cement becoming trapped against skin. A dry board alone is not a reliable barrier
• remove jewellery such as rings and watches, because wet cement can collect under them
• remove clothing contaminated by wet cement quickly, and wash skin that has touched wet cement at once with plenty of clean, cool water
• do not wash hands in water from buckets used for cleaning tools
• provide hygiene facilities on site so workers can wash their hands and face at the end of a job and before eating, drinking, smoking or using the toilet, and facilities for cleaning boots and changing clothes
• educate workers who handle, use or are exposed to dry or wet cement about the hazards and controls
• provide proper PPE to protect the skin from cement and cement mixtures
• carry out suitable health surveillance to check that the controls are preventing dermatitis

Legionella

Legionellosis is a collective term for diseases caused by legionella bacteria. The most serious is Legionnaires' disease, a potentially fatal form of pneumonia to which everyone is susceptible. Similar but less serious conditions are Pontiac fever and Lochgoilhead fever.

Outbreaks in workplaces are commonly linked to legionella growing in poorly maintained man-made water systems such as:

• cooling towers, evaporative condensers and fluid coolers that use evaporation to remove heat
• potable water systems and domestic hot water systems
• humidifiers, misters, foggers, and decorative or display fountains that create water spray
• spas, whirlpools and hot tubs
• cooling misters, produce misters and evaporative coolers
• industrial processes that create aerosolised water, such as cooling sprays, tanks, and water-based fluids used as coolants in cutting and fabrication

Typical controls include:

• control the release of water spray properly
• use a competent water-system control scheme. Where temperature is the control method, HSE guidance uses cold water below 20 °C and hot-water storage at least 60 °C, with suitable distribution monitoring and scald protection. Flushing or replacing water alone does not establish control
• make sure water cannot stagnate anywhere in the system, by keeping pipe lengths as short as possible or removing redundant pipework
• avoid materials that encourage legionella growth
• keep the system and the water in it clean
• treat the water to control the growth of legionella and other micro-organisms, or to limit their ability to grow
• monitor any controls applied and keep records of these and other actions, such as maintenance or repair work
• be aware of anyone with the symptoms of Legionnaires' disease

Summary notes for Element 7 · Cheat sheet · Glossary. A study aid, not published or endorsed by NEBOSH.