Thionyl dichloride

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Adequacy of study:

key study

Data source

Reference

Reference Type:

review article or handbook

Title:

Schwefeldioxid [MAK Value Documentation in German language, 1974, 1981, 1998, 2000, 2013]

Author:

Anonymous

Year:

2013

Bibliographic source:

Wiley-VCH Verlag GmbH & Co. KGaA, Published Online: 31 JAN 2012 DOI: 10.1002/3527600418.mb744609d0008

Materials and methods

Endpoint addressed:

other: MAK value documentation

Principles of method if other than guideline:

review

Test material

Test material information

Constituent 1

Reference substance name:

Sulphur dioxide

EC Number:

231-195-2

EC Name:

Sulphur dioxide

Cas Number:

7446-09-5

Molecular formula:

O2S

IUPAC Name:

oxosulfane oxide

Results and discussion

Results:

Sulfur dioxide irritates at concentrations of 5-10 ml/m³ (non-adapted persons) particularly the mucous membranes of the upper respiratory tract, at higher concentrations the eyes and mucous membranes, and with increased breathing the deeper airways. The irritation is caused by the hydration of sulfur dioxide on the moist mucous membranes, due to the formation of sulfurous acid (H2SO3).
The MAK value is based however not primarily to the irritating effect, but was from tudies with- probably hyperreactive - subjects in which during physical activity at concentrations from 0.6 to 2 ml/m³ a bronchoconstriction was found (Andersen et al 1974. Bedi et al 1984. Islam et al in 1992.; Koenig et al. 1982, Beermann et al. 1984, 1986; Rondinelli et al. 1987 Stacy et al. , 1981; Snell and Luchsinger, 1969).
In workers exposed to mean concentrations of 0.67 ml sulphur dioxide/m³, no changes in lung function parameters were observed, could be a habituation effect. Exposures of up to a 2-hour period with concentrations up to 0.5 ml/m3 caused in healthy volunteers no changes of the lung function.
In a study with 790 people, the concentration of 1 ml/m³ caused on 98% of the test persons not to decline in the FEV1 of more than 20% (Nowak et al. 1997). Since the people have been exposed at a respiratory minute volume of 40 I, it can be assumed that under workplace conditions with a lower respiratory minute volume (10 m³ per 8 hours, equivalent to 21 liters per minute), the proportion of workers who responds at 1 ml/m³ with bronchoconstriction will be below 2%.

TLV. The subjects in the study by Nowak et al. (1997) were exclusively exposed through the mouth. In a typical workplace respiratory minute volume of 21 l / min, about 60% is breathed through the nose (Bennett et al. 2003).
With nasal breathing, 90% of the sulfur dioxide from the air flow through the nose
is removed and didn’t reach the lungs (Speizer and Frank 1966). Also in dogs
has been shown that sulfur dioxide in the nose is removed more effectively than in the mouth.
In asthmatics it was shown, that during hyperventilation an airway obstruction on lower SO2 concentration is caused than at rest (Linn et al 1983. Sheppard et al. 1981).
The concentration is not alone determinative of the obstruction, but also the inhaled amount or depth of breathing. On nasal breathing with a respiratory minute volume of 21 l/min a lower amount of SO2 reach the lungs compared with mouth with a respiratory minute volume of 40 l/min.
Therefore, the MAK value is fixed at 1 ml/m³.

STEL. The short-term value-category I and the excess factor 1 are maintained.

Teratogenic effect.
In reproductive toxicity studies in mice and rabbits, at weak maternally toxic concentrations no evidence of teratogenic effects of sulfur dioxide were detected.
Naturally, about 750 mg sulphate/l urine (Supplement 1998) are excreted. Assuming a urine volume of 1.5 liters/day, a total amount of 1125 mg sulfate are excreted.
During a working day at an exposition corresponding to the TLV value with a tidal volume of 10 m³, about 27 mg of SO2 were adsorbed. Under the assumption of complete oxidation this corresponds to 40.5 mg sulfate and thus 1/30 of the daily excreted amount of sulphate. Thus, the daily absorbed amount of sulphate and the excreted sulphate in the urine increased only by 1/30 (3.33%). Therefore, sulfur dioxide remains the pregnancy group C.

Any other information on results incl. tables

Sulfur dioxide irritates at concentrations of 5-10 ml/m³ (non-adapted persons) particularly the mucous membranes of the upper respiratory tract, at higher concentrations the eyes and mucous membranes, and with increased breathing the deeper airways. The irritation is caused by the hydration of sulfur dioxide on the moist mucous membranes, due to the formation of sulfurous acid (H2SO3). The MAK value is based however not primarily to the irritating effect, but was from tudies with- probably hyperreactive - subjects in which during physical activity at concentrations from 0.6 to 2 ml/m³ a bronchoconstriction was found (Andersen et al 1974. Bedi et al 1984. Islam et al in 1992.; Koenig et al. 1982, Beermann et al. 1984, 1986; Rondinelli et al. 1987 Stacy et al. , 1981; Snell and Luchsinger, 1969). In workers exposed to mean concentrations of 0.67 ml sulphur dioxide/m³, no changes in lung function parameters were observed, could be a habituation effect. Exposures of up to a 2-hour period with concentrations up to 0.5 ml/m3 caused in healthy volunteers no changes of the lung function. In a study with 790 people, the concentration of 1 ml/m³ caused on 98% of the test persons not to decline in the FEV1 of more than 20% (Nowak et al. 1997). Since the people have been exposed at a respiratory minute volume of 40 I, it can be assumed that under workplace conditions with a lower respiratory minute volume (10 m³ per 8 hours, equivalent to 21 liters per minute), the proportion of workers who responds at 1 ml/m³ with bronchoconstriction will be below 2%. TLV. The subjects in the study by Nowak et al. (1997) were exclusively exposed through the mouth. In a typical workplace respiratory minute volume of 21 l / min, about 60% is breathed through the nose (Bennett et al. 2003). With nasal breathing, 90% of the sulfur dioxide from the air flow through the nose is removed and didn’t reach the lungs (Speizer and Frank 1966). Also in dogs has been shown that sulfur dioxide in the nose is removed more effectively than in the mouth. In asthmatics it was shown, that during hyperventilation an airway obstruction on lower SO2 concentration is caused than at rest (Linn et al 1983. Sheppard et al. 1981). The concentration is not alone determinative of the obstruction, but also the inhaled amount or depth of breathing. On nasal breathing with a respiratory minute volume of 21 l/min a lower amount of SO2 reach the lungs compared with mouth with a respiratory minute volume of 40 l/min. Therefore, the MAK value is fixed at 1 ml/m³. STEL. The short-term value-category I and the excess factor 1 are maintained. Teratogenic effect. In reproductive toxicity studies in mice and rabbits, at weak maternally toxic concentrations no evidence of teratogenic effects of sulfur dioxide were detected. Naturally, about 750 mg sulphate/l urine (Supplement 1998) are excreted. Assuming a urine volume of 1.5 liters/day, a total amount of 1125 mg sulfate are excreted. During a working day at an exposition corresponding to the TLV value with a tidal volume of 10 m³, about 27 mg of SO2 were adsorbed. Under the assumption of complete oxidation this corresponds to 40.5 mg sulfate and thus 1/30 of the daily excreted amount of sulphate. Thus, the daily absorbed amount of sulphate and the excreted sulphate in the urine increased only by 1/30 (3.33%). Therefore, sulfur dioxide remains the pregnancy group C.

Applicant's summary and conclusion

Executive summary:

Sulfur dioxide irritates at concentrations of 5-10 ml/m³ (non-adapted persons) particularly the mucous membranes of the upper respiratory tract, at higher concentrations the eyes and mucous membranes, and with increased breathing the deeper airways. The irritation is caused by the hydration of sulfur dioxide on the moist mucous membranes, due to the formation of sulfurous acid (H2SO3). The MAK value is based however not primarily to the irritating effect, but was from tudies with- probably hyperreactive - subjects in which during physical activity at concentrations from 0.6 to 2 ml/m³ a bronchoconstriction was found (Andersen et al 1974. Bedi et al 1984. Islam et al in 1992.; Koenig et al. 1982, Beermann et al. 1984, 1986; Rondinelli et al. 1987 Stacy et al. , 1981; Snell and Luchsinger, 1969). In workers exposed to mean concentrations of 0.67 ml sulphur dioxide/m³, no changes in lung function parameters were observed, could be a habituation effect. Exposures of up to a 2-hour period with concentrations up to 0.5 ml/m3 caused in healthy volunteers no changes of the lung function. In a study with 790 people, the concentration of 1 ml/m³ caused on 98% of the test persons not to decline in the FEV1 of more than 20% (Nowak et al. 1997). Since the people have been exposed at a respiratory minute volume of 40 I, it can be assumed that under workplace conditions with a lower respiratory minute volume (10 m³ per 8 hours, equivalent to 21 liters per minute), the proportion of workers who responds at 1 ml/m³ with bronchoconstriction will be below 2%. TLV. The subjects in the study by Nowak et al. (1997) were exclusively exposed through the mouth. In a typical workplace respiratory minute volume of 21 l / min, about 60% is breathed through the nose (Bennett et al. 2003). With nasal breathing, 90% of the sulfur dioxide from the air flow through the nose is removed and didn’t reach the lungs (Speizer and Frank 1966). Also in dogs has been shown that sulfur dioxide in the nose is removed more effectively than in the mouth. In asthmatics it was shown, that during hyperventilation an airway obstruction on lower SO2 concentration is caused than at rest (Linn et al 1983. Sheppard et al. 1981). The concentration is not alone determinative of the obstruction, but also the inhaled amount or depth of breathing. On nasal breathing with a respiratory minute volume of 21 l/min a lower amount of SO2 reach the lungs compared with mouth with a respiratory minute volume of 40 l/min. Therefore, the MAK value is fixed at 1 ml/m³. STEL. The short-term value-category I and the excess factor 1 are maintained. Teratogenic effect. In reproductive toxicity studies in mice and rabbits, at weak maternally toxic concentrations no evidence of teratogenic effects of sulfur dioxide were detected. Naturally, about 750 mg sulphate/l urine (Supplement 1998) are excreted. Assuming a urine volume of 1.5 liters/day, a total amount of 1125 mg sulfate are excreted. During a working day at an exposition corresponding to the TLV value with a tidal volume of 10 m³, about 27 mg of SO2 were adsorbed. Under the assumption of complete oxidation this corresponds to 40.5 mg sulfate and thus 1/30 of the daily excreted amount of sulphate. Thus, the daily absorbed amount of sulphate and the excreted sulphate in the urine increased only by 1/30 (3.33%). Therefore, sulfur dioxide remains the pregnancy group C.