This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth
Download 5.77 Mb.
|
Sensitisation
There are many published case reports and clinical studies that clearly indicate aqueous formaldehyde to be a human skin sensitiser (Lindskov, 1982; Andersen & Molhave, 1983; Cronin, 1991; Ebner & Kraft, 1991; Liden et al., 1993; Trattner et al., 1998). Indeed, formaldehyde solution has long been known as a cause of contact allergy and is included in all standard series for patch testing. Data from several recent patch tests studies are presented below, and support the conclusion that formaldehyde is a skin sensitiser.
30 common allergens including formalin and formaldehyde releasing preservatives. In addition, formaldehyde resins were included in the test when clinically relevant. The results are summarised in Table 11.2. Table 11.1: Irritative effect of gaseous formaldehyde in humans
Pulmonary irritation: No significant change in FVC, FEV1.0 and FEFR25 – 75 following exposure to 0.25, 0.4, 0.8 or 1.7 ppm formaldehyde. Comment: Individuals were asked to rate their level of discomfort. At all exposure levels, the highest individual rating was ‘discomfort’, which was the middle rating. The average rating for all exposures was ‘slight discomfort’. Following the first 2 hours exposure, 0.25 ppm caused more ‘discomfort’ that 0.4 ppm. The results are not published in a peer reviewed journal.
Comment: Eye irritation measured as percentage of subjects whose response time to formaldehyde was less than response time to clean air. Individuals were known to respond to formaldehyde (previously reporting eye irritation) and served as own controls. Table 11.1: Irritative effect of gaseous formaldehyde in humans (continued)
min every half hour
(10 volunteers) and 3 ppm (9 volunteers). Pulmonary irritation: No significant dose response in pulmonary function was observed (no further details available). Comment: authors estimated threshold values were Odour perception: < 0.5 ppm Eye irritation: 0.5 – 1.0 ppm Nose/throat irritation: 1.0 ppm
90 min None 18 (9 had previous complaints of effects to UFFI#) Eye and throat irritation: Following exposure to 1 ppm formaldehyde 83 % and 28 % of volunteers reported eye and throat irritation, respectively. Pulmonary irritation: No statistically significant change on FVC, FEV1.0 and FEFR25 – 75 following exposure to 1 ppm formaldehyde. Comment: complaints of eye and throat irritation were common in both groups (i.e. those previously complaining of effects to UFFI and those who had not) exposed to formaldehyde. Day et al., 1984 1.5 min None 48 Volunteers exposed to concentrations ranging from 0.3 – 4.0 ppm formaldehyde. The authors report that the irritation threshold was situated between 1 and 2 ppm. No further data available. Weber- Tschopp et al., 1977
5 min None 8 (4 males and 4 females) of which 1 male and 1 female Eye irritation: Mild to moderate irritation ratings seen following exposure to 1.65, 2.99 and 4.31 ppm. Severity was greatest 1.0 – 1.5 minutes after the onset of exposure and then declined. At 5 minutes, eye irritation ratings to 1.65 ppm and clean air (0 ppm) were comparable. Comment: Eye irritation reported to clean air with a slight increase in intensity seen with exposure Yang et al., 2001 were smokers duration. Table 11.1: Irritative effect of gaseous formaldehyde in humans (continued)
day) Pulmonary irritation: Pulmonary function measured 5, 15, 20 and 40 minutes after the onset of exposure. Compared to baseline values, no statistically significant decreases in FVC, FEV1.0, MEF50% and MEF40% were seen with exposure to 2 ppm formaldehyde during both resting and exercise. Comment: interpretation of the results by Paustenbach et al., (1997): eye irritation more sensitive parameter than nose and throat irritation.
day) Pulmonary irritation: pulmonary function measured 5, 15, 20 and 40 minutes after the onset of exposure. Compared to baseline values, no statistically significant decreases in FVC, FEV1.0, PEFR, MEF50% and MEF40% were seen with exposure to 2 ppm formaldehyde during both resting and exercise. Comment: authors concluded that persons exposed long-term to formaldehyde had similar upper respiratory symptom frequency and severity as persons not previously exposed (see Schachter et al., 1986). Table 11.1: Irritative effect of gaseous formaldehyde in humans (continued)
Pulmonary irritation: Although some reductions were seen to FEV1.0 and MEF50% over the exposure duration they occurred randomly with exposure to clean air and 2 ppm formaldehyde. No significant reduction was seen in FVC.
22 healthy Symptoms scored moderate to severe: Green et al., persons: intermittent strenuous activity persons (H) 16 asthmatics (A)
3.0 ppm (H) 3.0 ppm (A)
0 %
27 %** 19 %**
Odour Perception 0 %
23 %** 31 %**
Nose/throat irritation 0 %
32 %** 31 %**
1987 Asthmatics: intermittent moderate exercise Pulmonary irritation: Pulmonary function measured prior to exposure and 17, 25, 47 and 55 minutes after the onset of exposure. In healthy volunteers, and compared to control exposures, a statistically significant decrease of 2 %* on FCV was seen after 47 minutes to 3ppm and of 3 %* on FVC, FEV1.0 and FEV3.0 after 55 minutes exposure. No statistically significant reduction was seen at other assessment times or on FEFR25 – 75 in healthy volunteers, or on FVC, FEV1.0, FEV3.0 and FEFR25 – 75 in asthmatics. Comment: asthmatics were not more sensitive to the irritant effects of formaldehyde than non-asthmatics. Table 11.1: Irritative effect of gaseous formaldehyde in humans (continued) Duration Physical activity Number of volunteers Results Reference 2 hrs Intermittent physical exercise 24 healthy persons (non- smokers) Eye, nose and throat irritation: Compared with exposures to clean air, a statistically significant effect was seen at all time points on eye, nose and throat irritation with exposure to 3 ppm formaldehyde. Pulmonary function: Pulmonary function measured prior to exposure and 20, 50, 80 and 110 minutes after the onset of exposure. Compared to control exposures, a statistically significant decrease (< 10 %) in FEFR25 – 75 was only reported with 50 and 80 minutes exposure to 3 ppm formaldehyde. No statistically significant reductions were seen on FVC, FEV1.0 or FEV3.0. Comment: a significant formaldehyde effect on odour was also reported (no further details available). Green et al., 1989
3 hr Intermittent 9 healthy Individual scores for severity ranged from none to moderate: Sauder et al., 1986 Pulmonary irritation: Pulmonary function measured prior to exposure and 15, 30, 60, 120 and 180 minutes after the onset of exposure. Compared to control exposures, a statistically significant decrease of 2 %* on FEV1.0 and 7 %** on FEFR25 – 75 was seen only with 30 minutes exposure to 3.0 ppm formaldehyde. No statistically significant reduction was seen on FVC. Comment: individual responses to formaldehyde exposure ranged from –5% to +1% for FEV1.0 and – 14% to +2% for FEFR25 – 75.
Pulmonary function: Pulmonary function measured prior to exposure and 15, 30, 60, 120 and 180 minutes after the onset of exposure. Compared to control exposures, no statistically significant decrease in FVC, FEV1.0 or FEFR25 – 75 at any assessment time with exposure to 3.0 ppm formaldehyde. Comment: asthmatics were not more sensitive to the irritant effects of formaldehyde than non-asthmatics (see Sauder et al., 1986). Table 11.1: Irritative effect of gaseous formaldehyde in humans (continued) Duration Physical activity Number of volunteers Results Reference 20 min None 13 persons (2 males and 11 females) with symptoms of asthma. Eye, nose and throat irritation: Self-reports of eye, nose and throat irritation occurred as frequently with clean air [symptoms were not reported for the different exposure levels (0.1, 1.0 and 3.0 ppm)]. Pulmonary function: Pulmonary function measured prior to exposure, immediately after and up to 24 hours after the onset of exposure. Compared with exposures to clean air, no significant decrease reported in FEV1.0 or FEFR25 – 75 with exposure concentrations up to 3.0 ppm formaldehyde. Comment: Of the 13 subjects, 3 and 5 subjects were not challenged as they had unequivocal or convincing histories of asthma, respectively, 2 subjects were not challenged with methacholine because of time restraints, and 1 of remaining 3 gave a positive challenge to methacholine. Reed & Frigas, 1984
* Significantly different from control (p < 0.05) ** Significantly different from controls (p < 0.01) *** Significantly different from control (p < 0.005) **** Significantly different from controls (p < 0.02)
FEV1.0, Forced expiratory volume in one second FVC, Forced vital capacity MEF50%, Maximum expiratory flow at 50% of vital capacity PEFR, Peak expiratory flow rate Ppm, Parts per million Over a 2-year period in a Danish dermatology clinic, of 40 patients who gave a positive patch test to their own cosmetic products, 5 (12.5%) gave a positive result to formaldehyde (Held et al., 1999). In a Finish dermatology clinic, 82 of 1414 patients (5.8%) patch tested over a 6-year period with a modified European standard series gave a positive result to 1% formaldehyde solution (Kanerva et al., 1999). As part of a study on occupational skin diseases, 223 nurses were patch tested with a supplemented European standard series and prick tests conducted for common allergens (Kiec-Swierczynska, 2000). Prick tests indicated 80 (36%) nurses were atopic. A positive patch test to 1.0% formaldehyde solution was observed in 46 nurses (20.6%). A case report is available of a 30-year old man who developed occupational allergic dermatitis working in a clothing warehouse (Cockayne et al., 2001). Formaldehyde resins, which were used in the textile industry, were suspected. Positive patch tests were reported with aqueous formaldehyde and formaldehyde resin. Table 11.2: Case report of skin sensitisation by ODREC*
*All workers were tested for formalin, but not all were tested for formaldehyde resins. The names in bracket are trade names. A number of human studies were conducted to induce (Marzulli & Maibach, 1974) and elicit skin sensitisation in sensitised individuals [Marzulli & Maibach, 1973 cited in the IPCS review (1989); Jordan et al., 1979; Hilton et al., 1998]. The CICAD (IPCS, 2002) concluded that the concentration of formaldehyde likely to elicit contact dermatitis reactions in hypersensitive individuals may be as low as 30 mg/L (0.003%). ATSDR (1999) concluded that allergic skin responses in sensitised individuals exposure to concentrations below 0.25% to 0.05% formaldehyde in solution are rare. There are no human data to suggest that exposure to formaldehyde gas causes skin sensitisation.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||