Respiratory Hazards & COSHH Flashcards

What respiratory hazards arise from welding on construction sites?

Answer: Metal fumes (including hexavalent chromium from stainless steel), ozone, nitrogen oxides, and UV radiation effects on the respiratory system

Welding generates complex fume mixtures including metal oxides (iron, manganese, chromium), ozone from arc UV, and nitrogen oxides. Stainless steel welding produces hexavalent chromium, a known carcinogen. Local exhaust ventilation is essential.

In 2019 the HSE changed its guidance on welding fume. What was the key change?

Answer: Mild steel welding fume was reclassified as a carcinogen — LEV is now required for all welding indoors

In 2019 the International Agency for Research on Cancer (IARC) reclassified all welding fume (including mild steel) as Group 1 carcinogens. The HSE updated guidance to require LEV for all indoor welding and suitable RPE where LEV alone is insufficient.

What is wood dust and why is it a health hazard on construction sites?

Answer: Fine dust from machining or cutting wood — hardwood dust causes nasal cancer; both softwood and hardwood cause asthma

Wood dust is a significant respiratory hazard. Hardwood dust (oak, beech) is classified as a human carcinogen causing sinonasal cancer. Both hardwood and softwood dust can cause occupational asthma. LEV and RPE are required for dusty wood-working operations.

Which type of respirator provides the highest protection factor for construction respiratory hazards?

Answer: A powered air-purifying respirator (PAPR) or a supplied air breathing apparatus (SABA)

Powered air-purifying respirators (PAPR) and supplied air breathing apparatus (SABA) provide the highest levels of respiratory protection, with assigned protection factors up to 40 or more. They are required for the highest risk exposures like asbestos removal.

What is occupational asthma and how does it differ from common asthma?

Answer: Asthma caused by sensitisation to a workplace substance — it can occur in people with no prior asthma history and may become permanent

Occupational asthma is caused by sensitisation (an immune response) to a workplace substance. Once sensitised, even tiny exposures trigger attacks. It can develop in previously healthy individuals and, if exposure continues after diagnosis, can become permanent even after leaving the job.

What is the correct storage requirement for chemicals on a construction site under COSHH?

Answer: Segregated, labelled, in appropriate containers, with incompatible chemicals stored separately and a bunded secondary containment where required

Chemical storage must be segregated by hazard type (flammables, oxidisers, and corrosives must not be stored together as they can react). Containers must be appropriate, clearly labelled, and secondary bunding provided to contain spillage. Quantities should be minimised.