General Profile

Cleaning consists of dusting, washing and polishing surfaces; washing walls; mopping, sweeping and polishing floors; as well as disposing of waste and waste water. It is done in offices, public and commercial buildings, homes and factories. It may be done in confined spaces with little ventilation and in spaces not designed with cleaning in mind. Cleaners may be independent or be employed by the enterprise which owns the facilities being cleaned, or they may work for private contractors. Those who clean may be called cleaners, housekeepers, chars, custodians or janitors, depending on the spaces cleaned and the details of the assigned tasks. For example, janitors and custodians may combine cleaning with maintenance and repair work.

Cleaners have usually worked relatively autonomously, compared to other employment categories of similar prestige. Inspection is done by supervisors, although the users of the cleaned spaces also comment on the cleaners’ work. Workers tend to order the tasks themselves and develop their own procedures (Messing, Haëntjens and Doniol-Shaw 1993). However, in commercial spaces in North America, cleaners’ routes have increasingly been determined using software programmed to take account of furniture, floor surfaces and crowding. The desired frequency of operations, area to be cleaned and time estimated for the type of area are used to calculate the total time required. Inspection may be done using a computer-programmed spot check procedure. Some of these procedures may severely underestimate the task as performed in shared space, especially if the inventory is not brought regularly up to date (Messing, Chatigny and Courville 1996).

In Canada, cleaning is the eighth most common profession of men and the tenth most common profession of women; women make up 46% of the profession (Armstrong and Armstrong 1994). In France in 1991, 229,000 cleaners worked for 9,000 cleaning companies; about a third were immigrants and 64% were women (Bretin 1994). In Denmark 85% of the 130,000 cleaners are women (Nielsen 1995). In some countries, tasks in factories and services have often been divided into “light” and “heavy”, assigned formally or informally to female and male workers respectively, who may be paid at different rates (Government of Quebec 1994). Women may dust and polish surfaces, clean bathrooms and empty wastebaskets while men sweep, mop and polish floors and carry waste to incinerators (Messing, Haëntjens and Doniol-Shaw 1993; Messing, Doniol-Shaw and Haëntjens 1993; Messing, Chatigny and Courville 1996). In other countries, men and women can be assigned to all cleaning tasks (Nielsen 1995; Hagner and Hagberg 1989). Cleaners are often relatively old compared to other workers (Bretin et al. 1992; Messing 1991; Nielsen 1995).

Risk Factors and Prevention Strategies

Cleaning may be done with hand-held tools such as brushes, brooms, rags and mops, or may be aided by machines. A variety of chemicals are used to dissolve dirt and to make surfaces appear clean and shiny. The difficulty of the task varies according to the type of surface (rough, smooth, pitted), the height and geometry of the objects cleaned, the degree of crowding of spaces and the vocations exercised in the spaces cleaned. In some places, the need for cleaning may be reduced or eliminated by design changes in the object cleaned (such as self-flushing toilets).

Musculoskeletal load

Cleaning, particularly cleaning furniture and bathrooms and emptying wastebaskets, involves rapid postural changes and many awkward and constrained postures (see table 1). Many objects must be cleaned, at a variety of heights; a typical sequence observed for dusting in a hospital room was: table (81 cm), television (196 cm), table (81 cm), telephone (81 cm), lamp (extends to 188 cm), table foot (11 cm), chair (46 cm), screen (81 cm), armchair (46 cm), window ledge (89 cm), wall sphygmomanometer (154 cm), chair legs (floor to 46 cm), oxygen fixture (137 cm) (Messing, Chatigny and Courville 1995).

Table 1. Postures observed during dusting in a hospital.

Source: Messing, Chatigny and Courville 1995.

Floor cleaning requires repeated movements (fundamental cycle time of 1 to 2 seconds in the Sogaard, Fallentin and Nielsen (1996) study) and a sustained moderate bending of the back. Constant pressure is exerted by the hands to push vacuum cleaners or buffers, tasks requiring forces near 10 kg (Messing, Chatigny and Courville 1996). Sogaard, Fallentin and Nielsen (1996) found mean back bending during floor mopping to be 28º and mean neck bending to be 51º. Hagner and Hagberg (1989) also noted static muscular loads especially at the shoulder joint. Nordin et al. (1986) found extensive forward trunk bending in a simulated janitorial task involving floor mopping. Cleaning floors and objects is usually done with repeated movements. Sogaard (1994) suggests that the sustained repetitive motions with infrequent pauses in activity may exhaust the relatively small numbers of muscle fibres involved and result in muscular disorders.

In order to clean, many objects must be moved. During 66 minutes cleaning and polishing floors, 0.7 objects had to be moved per minute, with weights up to 10 kg; during 23 minutes of dusting, 3.7 objects were moved per minute, with weights up to 2 kg (Messing, Chatigny and Courville 1995).

Winkel et al. (1983) and Hagner and Hagberg (1989) note that increasing specialization and standardization have reduced the number of opportunities to vary body movements and postures during cleaning work. It is therefore important to provide adequate break time. Formal or informal division of tasks according to sex may increase the likelihood of musculoskeletal problems by decreasing the variation in movements (Messing, Haëntjens and Doniol-Shaw 1993).

Cardiovascular load

The cardiovascular load can be quite heavy. Johansson and Ljunggren (1989) recorded the heart rate of female cleaners during office or toilet cleaning at 123 beats/minute, 65% of the maximum for their average age of 29.8 years (corresponding to about 35% of their estimated maximal oxygen uptake or VO_{2 max}, close to that of construction workers). Swabbing or mopping resulted in similar heart rates of 122 to 127 beats/minute. Hagner and Hagberg (1989) found a high level of oxygen consumption (up to 40% of the VO_{2 max}) among cleaners doing floor mopping under experimental conditions. Sogaard (1994) found that relative cardiovascular strain of female school cleaners measured in the workplace was 53% of the VO_{2 max}.

To prevent musculoskeletal problems and decrease the cardiovascular load, workload should be appropriate and sufficient rest time should be allowed. Attention should be paid to ease of cleaning when spaces and procedures are being designed and when furnishings are purchased. Vacuuming requires less force if carpets are carefully laid so as not to wrinkle when the vacuum cleaner is passed. The use of adequate tools is important. For example, extendable brushes for dusting can reduce the necessity to reach or climb. Prolonged bending can be minimized if efficient chemicals and tools make it possible to clean quickly, and if cleaning is frequent enough so that dirt does not become hardened.

The common practice of reducing the rate of ventilation in buildings during the evening or night hours, when cleaning is done, reduces air quality for cleaning workers who work during these times and should be avoided. To prevent overwork in the case where cleaning is planned using purchased software, careful observation and verification should be done in order to make sure that times allotted are realistic and take into account multiple use of spaces cleaned. Inventories of rooms and objects cleaned should be updated frequently.

Procedures and apparatus for emptying wastebaskets into bins, and bins into incinerators, have been developed so that manual lifting can be avoided.

Chemicals

Chemicals can be classed as soaps, detergents, disinfectants, porcelain cleaners, scouring powders, wax removers and strippers, solvents, pesticides and drain cleaners. They may contain other ingredients such as fragrances and colouring agents. There may be surface skin contact or they may be inhaled or absorbed through the skin into the system. Damage to the skin, eyes, throat or lungs can result. The risk of exposure depends on the concentration of the chemical and how it is used. Sprays volatilize chemicals and increase exposure. Some chemicals are irritants at low concentration and corrosive at high concentration (acids, oxidizing agents or bases). Others are effective solvents or detergents which may damage the skin barrier and make it more vulnerable to other chemical agents. Still others contain metals (nickel, cobalt, chrome) or other substances which can act as allergens.

Cleaning agents are often sold at high concentrations and diluted on site for use. The common practice of using chemicals at a higher concentration than recommended, in the hope of cleaning more quickly or more efficiently, is a source of overexposure and should be remedied by proper education and by adjusting the workload. Mixing different chemicals can cause accidental intoxication or burns. Work with strong chemicals in poorly ventilated spaces can be a hazard for cleaners and should be avoided.

The Danish Product Register Data Base PROBAS contains information on 2,567 washing and cleaning agents. Of these, 70 are considered to be potentially harmful agents causing chronic or acute health damage, such as corrosives, carcinogens, reproductive toxicants, allergens and neurotoxic agents (Borglum and Hansen 1994). These agents are presented in table 2. A study of the PROBAS register found 33 contact allergens in cleaning agents (Flyvholm 1993).

Table 2. Dangerous chemicals used in cleaning.†

A = allergen; C = corrosive; I = irritant; K = carcinogen; N = neurotoxic agent; R = reproductive toxic agent; T = toxic if swallowed; * = danger dependent on concentration.

Determination of toxicity was done by the Danish Institute of Occupational Health.