Health and Safety
Executive / Commission
Local authority circulars
To: Directors of Environmental Health/ Chief Environmental Health Officers of London, Metropolitan, District and Unitary Authorities and Chief Executives of County Councils.
For the attention of: Environmental Services / Trading Standards / Fire Authorities / Other
This circular gives advice to local authority enforcement officers
1 This local authority circular summarises the results of recent studies on ill health effects of flour dust in bakeries, including a recent Scottish Regional project on flour dust in craft bakeries.
2 Asthma has been associated with work in bakeries for several centuries. From individual reports in more recent years and from the number of cases of asthma attracting compensation from the Department of Social Security, HSE has been aware that a problem exists. However, detailed information on the extent of the problem, the severity of the problem and the relationship between dust levels and illness has not been clear.
3 Although still somewhat sparse compared with data on other harmful substances, in recent years the information on the ill health effects of flour dust has been accumulating. The purpose of this circular is to introduce these recent findings.
4 A voluntary scheme for the surveillance of work related and occupational respiratory disease (SWORD) was established in January 1989 with help from the British Thoracic Society and the Society of Occupational Medicine. This work is supported from a grant by HSE.
5 The results of the first year of operation of this scheme were reported by Meredith et al (Occupational Disease in the United Kingdom 1989: A Report to the British Thoracic Society and the Society of Occupational Medicine by the SWORD project group, British Journal of Industrial Medicine 1991; 48: 292-298).
6 In 1989 2,101 cases of newly diagnosed work related respiratory illness were reported. Asthma was the most frequent diagnosis with 554 (26%) cases. Flour/grain dust was the suspected agent in 42 (8%) of those cases.
7 Annual incidence rates were calculated per million working population. The overall rate for asthma was 22 per million. Twenty nine cases of asthma in bakers were diagnosed giving an annual incidence rate of 409 per million, almost 20 times more than the overall rate and giving bakers the third highest ranking of any occupational grouping.
8 To determine the extent, nature and seriousness of work related ill health among bakery employees and to examine the relationships between ill health, airborne dust levels and immunological sensitisation, a study was carried out by HSE staff in 18 small bakeries across central Scotland.
9 In response to questionnaires to 224 employees a total of 162 respondents (72% or respondents) reported at least one ill health symptom and 98 of these (44% of respondents) were classified as work related according to the definition "worse at work or better when on holiday for a week or more". Work related nasal/eye symptoms were most common (27%), then asthma type (21 %), coughs (20%) and chronic bronchitis (7%). The overall rates or reporting of these were 46% (asthma type), 45% (cough) and 9% (chronic bronchitis). All symptoms were reported at higher levels by those doing dustier jobs and asthma and nasal symptoms were associated with longer employment in the bakeries. Smoking made no difference to the reported level of any symptom.
10 Total dust exposures ranged from 0.1 to 23.7 mg/m3, 8 hour time weighted average. Respirable dust varied from less than 0.01 to 3.6 Mg/M3. On average respirable dust was 11% of total dust. Highest dust levels were associated with hand moulding and dividing, weighing and mixing and operating baking plant (eg dough brake, roll plant). Overall 15% of employees were exposed to total dust levels greater than 10 mg/m3. For those handling flour directly this figure rose to 24%. Use of a direct reading visualisation concerning technique indicated that short duration exposures to much higher levels commonly occurred.
11 Work related asthma type symptoms were linked to having antibodies (IgE) to wheat flour, storage mite and house dust mite. Sensitisation to wheat, rye and mite was associated with work related nasal symptoms and bronchitis. Those with work related symptoms were significantly more likely to be sensitised to workplace allergens than those without symptoms.
12 Copies of the report on this study, "111 Health in Workers in Small Bakeries, Dust Levels and Immunological Sensitisation - Report of a Study of 18 Bakeries in Central Scotland by Staff of HSE", entitled "A seriological investigation of workers in small bakeries in Scotland' (IR/L/IM/92/01) dated 1992 - Internal Report Collection; can be examined via your ELO. These have been given to the participating bakeries, to the bakery trade associations, via the Health and Safety in Bakeries Liaison Committee, and trade unions representing bakery employees.
13 Both of these studies provide evidence for the existence of widespread occupational ill health in bakery workers Additionally, the HSE study indicates a significant level of excessive dust exposure and high levels of immunological sensitisation to workplace allergens.
14 Because it is such an everyday material in use in people's homes the view that it can be a risk to health is for many people a somewhat difficult idea to take seriously. The evidence indicates clearly that in terms of occupational asthma bakers are the third most at risk occupational group. Perceptions of how serious a problem asthma is may also influence attitudes towards this Problem. There is no doubt that asthma can be very serious or even a fatal illness.
15 There is a growing acceptance in the industry of the need to control flour dust and monitor health. However, whilst the industry accepts that better supervision and less dusty working practices must be the first approach there is, as yet, less agreement about the balance between the prevalence and severity of ill health against the cost of engineering methods to control dust where plant is only used for shorter periods - eg in small bakeries.
16 Guidance on health surveillance and practical methods of control has been produced by the Health and Safety in bakeries Liaison Committee. This comprises representatives of the bakery trade associations, Health and Safety Executive and the Bakers Food and Allied Trade Union. The guidance is entitled "Guidance on practical measures to control dust in bakeries', it is available for issue by the constituent organisations of the Health and Safety in Bakeries Liaison Committee for whom it was printed by the National Association of Master Bakers, 21 Baldock Street, Ware, Hertfordshire, SG1 2 9DH, tel: 0920 468061. The guidance complements existing guidance on the subject entitled "Guidance to Bakeries on the Implementation of the Control of Substances Hazardous to Health Regulations 1986'.
17 Although the guidance has been agreed the bakery trade still has some concerns. Firstly, there is debate about the extent of ill health caused by exposure to dust in bakeries. The scientific literature is not extensive and some of the evidence pointing to the existence of a problem is based on the responses to questionnaires rather than actual diagnosis it ill-health. This is a point which under-pins much of the trade's concern.
18 The second concern relates particularly to very small bakers. Trade representatives argue strongly with some justification that apart from any financial considerations there is very little room in small bakeries for bulky local exhaust ventilation equipment. The view of the HSE Food National Interest Group is that such equipment will be necessary if the other recommended control measures do not achieve adequate control. It is because of this concern that there is so much emphasis in the guidance on tailoring the exact precautions to the individual requirements of any particular bakery.
19 Implicit in the guidance is a recognition of the fact that things are not going to change overnight. It is for this reason that a simple 4 step approach is adopted starting with health surveillance and followed by efforts to control very high exposures, exposures greater than 10mg/m3 and then exposures less than 10mg/m3. The HSE Food National Interest Group advice is that enforcement of dust levels below 1 0mg/m3 should only be considered where good evidence of high dust levels and ill health exists.