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McCoach JS, Robertson AS, Burge PS , Floor cleaning materials as a cause of occupational asthma , Indoor Air , 1999 ; 99:5 : 459-464

FLOOR CLEANING MATERIALS AS A CAUSE OF OCCUPATIONAL ASTHMA

J.S. McCoach, A.S. Robertson and P.S. Burge

Occupational Lung Disease Unit, Department of Respiratory Medicine, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham. B9 5SS, UK.

ABSTRACT
Floor cleaning materials are increasingly being recognised as a cause of asthma in the workplace. In the West Midlands (UK) alone, there have been seventeen cases of occupational asthma reported to Shield where the most likely or proven cause was the floor cleaning material. There are a number of common constituents present in these materials which are possible causes of occupational asthma, the most frequently occurring substances are rosins, i.e. colophony based products, and benzalkonium chloride. Eight of the reported workers have completed serial peak flows analysis by OASYS-2 confirming occupational asthma. Six of these workers also underwent specific bronchial provocation tests to the constituents of the floor cleaning materials. In all of these cases, the results have confirmed that the floor cleaning materials are the cause of their occupational asthma. Most of the workers were only indirectly exposed in their workplace. Floor cleaning materials should be considered as a cause of occupational asthma when a direct cause is absent.

INTRODUCTION
Floor cleaning agents are seldom recognised as a cause of occupational asthma, even though they contain a range of chemicals. Floors are often cleaned on a regular basis in the absence of the usual workforce. There are an extensive range of floor cleaning materials, many of which now attempt to sterilise as well as clean. Their safety data sheets often do not reveal all of the constituents. Our recent investigations have suggested that there is evidence of some common chemicals in cleaning agents, that are responsible for occupational asthma. Colophony is a well-established cause of occupational asthma when present in electronic solder flux [1] [2]. Rosins, Le. colophony based products such as pine oil and tall oil, are frequent constituents of industrial cleaning agents, and has caused occupational asthma without heating in a coating manufacturer [3]. Tall oil contains colophony [4], and has causes asthma in tyre manufacture [5]. Benzalkonium chloride is also a common constituent of industrial cleaning agents, it has been described as a cause of occupational asthma in a laundry worker [6], and in the pharmacist also included in this paper [7].
The aim of this investigation was to examine the possible roles of cleaning agents and their constituents in cases of occupational asthma reported to the Shield surveillance scheme. Shield is a voluntary reporting scheme for occupational asthma covering 2.2 million workers in the West Midlands region (UK) [8].

METHODS

1. Cases of occupational asthma reported to Shield were identified. Seventeen cases have been examined.

2. Eight of the seventeen workers completed serial peak expiratory flow (PEP) measurements approximately 2-hourly over periods at and away from work. The serial PEF records were analysed by the OASYS-2 system [9].

3. In cases where occupational asthma has been confirmed with serial PEF records, but the cause unknown, a workplace visit was arranged.

4. Six workers had specific occupational-type bronchial provocation testing in hospital. These tests were recommended as serial peak flows had confirmed occupational asthma and the cause of which, was uncertain. Tests were made on separate days with monitoring of FEVl for at least eight hours after each exposure. Exposures were made with the whole cleaner, or constituents of the cleaners, diluted to their recommended working concentrations. The cleaning material was painted onto card in a sealed challenge chamber. Control exposures were made with alternative cleaning materials.

5. Once the cause of occupational asthma has been confirmed, recommendations were made for a change in floor-cleaning material and the exposed affected workers re-monitored with serial PEF measurements.

RESULTS

Shield. The database contains a total of 1537 cases of occupational asthma, in 17 (1.1% of the total) the cause was thought to be floor cleaning agents (Table 1). Six of the 17 workers (35%) were directly exposed to the floor cleaning agents as domestic cleaners. 11 of the 17 workers (65%) were indirectly exposed to these agents, and had a variety of occupations. There were 5 teachers, 1 pharmacist, 1 laboratory technician, 1 abattoir worker, 1 VDU operator, 1 secretary and 1 caretaker (who might have done occasional cleaning). Latent intervals from the start of the current employment to the first symptom of occupational asthma ranged from 2-10 years, there was, however, inadequate records of the use of cleaning materials to date the onset of exposure to the agent responsible for the occupational asthma. Only three of the seventeen reported workers were current smokers.

Eight sets of serial PEF records were analysed by OASYS-2 (Table 1). In 6 the Oasys-2 score exceeded 2.51, where occupational asthma is confirmed. The score was lower in the remaining two, in these two the expert interpretation confirmed occupational asthma.

Bronchial Provocation Tests were performed on 6 of the 17 workers. The agents that were used were Applied 310 Ni-Gel, Vantropol FHC, Jangro Neptune, Triple Fresh and Triple Buff The workers demonstrated positive reactions when challenged to the respective cleaning agents and were subsequently exposed to their constituents. Reactions were reproduced with separate exposures to either tall oil or benzalkonium chloride, depending on the specific contents of the cleaning material Examples of the challenge graphs are shown in figures 1 and 2.

Table 1

A table to show the worker details, exposure and provocation test results

Case No.	Sex	Age	Occupation	Name of cleaning agent	Positive challenges	OASYS score	Length of Latent Interval	Smoking History	
1	F	52	School cleaner	Applied 5-417	Not done	N/A	8 YRS	EX	
2	F	56	Caretaker	Applied 5-417 & Grangel	Not done	N/A	3YRS	NEVER	
3	F	37	VDU Operator	Cleaner	Not done	N/A	3 YRS	NEVER	
4	F	68	Teacher	Cleaner	Not done	>2.51	10 YRS	EX	
5	F	53	Teacher	Cleaner	Not done	<2.51	2YRS	NEVER	
6	F	65	Teacher	Cleaner	Not done	N/A	3 YRS	EX	
7	F	53	Cleaner	Cleaner	Not done	N/A	2 YRS	SMOKER	
8	F	49	Lab technician	Applied 3 10 Ni-Gel	Applied 3 10 & TaD oil	3.3	6 YRS	NEVER	
9	F	44	Art teacher	Applied 310 & Jangro Neptune	Rosins & Tall oil	3.5	8 YRS	NEVER	
10	M	32	Contract cleaner	Applied 310 Ni-Gel & Meget	Applied 3 10 & Tall oil	>2.5	3YRS	EX	
11	F	64	Teacher	Applied 5-417 & Pine cleaner	Not done	N/A	2 YRS	EX	
12	F	43	Secretary	Triple Buff & Triple Fresh	Rosins & Benzalkonium chloride	<2.51	2 YRS	NEVER	
13	F	52	Cleaner	Compublend	Not done	N/A	3 YRS	EX	
14	F	56	Cleaner	Compublend	Not done	N/A	2 YRS	SMOKER	
15	F	68	Cleaner	Compublend	Not done	N/A	2 YRS	NEVER	
16	M	42	Abattoir worker	Power Wash	Benzalkonium chloride	>2.51	6 YRS	SMOKER	
17	M	56	Pharmacist	Vantropol FHC	Benzalkonium chloride	4.00	9YRS	NEVER	

Figure 1.

Figure 1 shows the results of the provocation tests in the laboratory technician. She painted the correctly diluted solution onto cardboard, for a similar length of time. Following a control exposure to a detergent cleaner, she experienced no symptoms. Following the exposure to Applied 310 she developed wheeze, breathlessness, nausea, coughing and some joint pains similar to those experienced at work. There was a reduced FEV 1 which stayed below the 15% baseline for upto 2 hours post-challenge. Similar symptoms and FEV1 reduction followed exposure to tall oil alone.

Figure 2

Figure 2 shows the results of the series of bronchial provocation tests that a school art teacher undertook. She underwent similar provocation tests to the worker as shown in figure 1. She showed no reaction to a detergent cleaner, but showed positive reactions to the Applied 310 and Jangro Neptune. On both challenge days, the FEV 1 was reduced to below the 15% baseline for up to 2 hours post-challenge. She had a similar reaction to tall oil on a separate challenge.

The Outcome
The school laboratory technician unproved dramatically when the school's floor cleaning agent was replaced. Interestingly, the reported joint pains also improved and hair & eyelash growth returned. The school art teacher started to show improvements after the floor cleaning agents were replaced, but occupational asthma re-commenced when different cleaning agents containing benzalkonium chloride were introduced. In the other four cases of workers who underwent bronchial provocation tests, the worker was either relocated or the floor cleaning agent was removed from the site, and in each case symptoms were remarkably improved.

CONCLUSIONS

Until recently, floor cleaning agents have not been recognised as a cause of occupational asthma. These investigations indicate that such agents are a possible cause of asthma in the workplace. None of the safety data sheets that accompanied these cleaning agents listed respiratory sensitisation as a possible hazard. Colophony, which is a well established cause of asthma, has mostly been associated with solder flux. Colophony in tall oil is a common constituent now found in many floor cleaning agents. Benzalkonium chloride is a less well recognised cause of occupational asthma in other situations.
The particular importance of this study is that the exposures were often indirect, the affected worker not being present when the cleaning took place. There was sufficient residue of cleaning materials on the floors or work surfaces to cause the occupational asthma. Several floor and surface cleaners are now sprayed rather than mopped, which will increase the respiratory exposures to the cleaners themselves.

REFERENCES

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2) P.S. Burge, M.G. Harries, I. OJBrien and J. Pepys. Bronchial Provocation Studies In Workers Exposed To The Fumes of Electronic Soldering Fumes. Clinical Allergy. 1980; 10: 137-49.

3) Burge PS, Weiland A, Robertson AS, Weir D. Occupational asthma due to unheated colophony. British Journal of Industrial Medicine. 1986; 43: 559-580

4) EE McSweeney, G Herbert, J Russell Tall oil and its uses. Pulp Chemical Assoc. Inc. New York, 1987

5) SM Tarlo Occupational asthma induced by tall oil in the rubber tyre industry. Clinical and Experimental Allergy 1992; 22: 99-101

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