Effectiveness of ultraviolet light personal protective equipment used by informal sector arc welders in Machakos town, Kenya

  • E Muthusi
  • R Kinyua
  • C Mburu
Keywords: Personal protective equipment, arc welder, informal sector/jua kali, ultraviolet light, shade number, filter plate


The purpose of the study was to evaluate the suitability of the ultraviolet (UV) light personal protective equipment (PPE) used by arc welders in the informal sector. Primary data were collected through a survey in the study area and through laboratory test of the identified UV light PPE’s filter plates. A sample of one hundred and three arc welders in the study area was accessed through snowball sampling technique since cases were affiliated through links that could be exploited to locate other respondents based on existing ones. The study involved both the owners of the workplaces and their staff operating in the Kenya Industrial Estates (KIE) sheds, Masaku Jua Kali Association sheds and the individual arc welders operating along the streets of Machakos Town, Kenya. All the arc welders who participated in the study except one were 18 years and above in age and all had formal education: 31.1% had primary school level as the highest attained education level, 34.9% had secondary school level as the highest attained education level and 34.0% had been to tertiary learning institutions. The field survey identified nine types of UV light PPE used by the study group. The PPE were identified by the distinct features on their filter plates: shade number 12, shade number 11, gas goggles, dark dots, dark vertical lines, dark horizontal lines, dark spiral lines, dark nucleus and obstruct glass. Absorbance of each filter plate at max in the UV range of the electromagnetic spectrum as determined so as to calculate the corresponding shade number. The absorbance values matched that of shade number 12, 11, 9 and 8. The study found out that 63.1% of the arc welders used shade numbers 8 and 9 both of which were below the minimum recommended shade number 10 for arc welding in the lense selection guide. The effectiveness of the UV light PPE used was influenced by the highest level of education attained by the arc welder, the age of the welder and the number of years the welder had worked as arc welder in the informal sector (p < 0.05). The peculiar nature of the activities constituting arc welding in the informal sector requires modified goggles with scientific proof of their effectiveness and not hand‐held welding shield or the welding helmet.

Key words: Personal protective equipment, arc welder, informal sector/jua kali, ultraviolet light, shade number, filter plate


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eISSN: 1561-7645