Sulphuric acid

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-standard published study

Data source

Reference

Reference Type:

publication

Title:

Inhalation Of Sulfuric Acid Mist By Human Subjects

Author:

Amdur MO, Silverman L & Drinker P

Year:

1952

Bibliographic source:

Archives of Industrial Hygiene and Occupational Medicine, Vol. 6, No. 4, pages 305-31

Materials and methods

Study type:

study with volunteers

Endpoint addressed:

acute toxicity: inhalation

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Investigation of the respiratory effects of sulphuric acid mist inhalation

GLP compliance:

no

Remarks:

: not applicable

Test material

Test material information

Constituent 1

Reference substance name:

Sulphuric acid

EC Number:

231-639-5

EC Name:

Sulphuric acid

Cas Number:

7664-93-9

Molecular formula:

H2O4S

IUPAC Name:

sulfuric acid

Details on test material:

Sulphuric acid mist

Method

Subjects:

Male (unspecified number)

Route of exposure:

inhalation

Reason of exposure:

intentional

Exposure assessment:

measured

Results and discussion

Results of examinations:

Lung retention of sulfuric-acid averaged 77 percent. Exposures to the lower concentrations of mist caused more shallow and more rapid breathing. The period of expiration was prolonged, averaging 69.3 percent of the breathing cycle versus 59.6 percent of the cycle when the subjects breathed air. At sulfuric-acid concentrations of 5mg/m3, the effects of the mist on respiration were more varied. The major response was a decrease in minute volume.

Any other information on results incl. tables

Lung retention of sulfuric-acid averaged 77 percent. Exposures to the lower concentrations of mist caused more shallow and more rapid breathing. The period of expiration was prolonged, averaging 69.3 percent of the breathing cycle versus 59.6 percent of the cycle when the subjects breathed air. At sulfuric-acid concentrations of 5mg/m3, the effects of the mist on respiration were more varied. The major response was a decrease in minute volume.

Applicant's summary and conclusion

Conclusions:

The authors note that sulfuric-acid mists having concentrations below 3mg/m3 are not normally detectable. They conclude that respiratory changes induced by inhaling sulfuric-acid mists at concentrations on the order of 0.35mg/m3 are purely reflexive in nature. The more shallow, more rapid breathing may be a reflex protective mechanism to decrease the retention of acid mist particles.

Executive summary:

The effects of inhaling sulfuric acid mist were studied in humans. An unspecified number of normal male subjects inhaled sulfuric-acid aerosols at concentrations ranging from 0.35 to 5 milligrams per cubic meter (mg/m3). The subjects were at rest during the exposures and breathed through a face mask. Exposure times ranged from 5 to 15 minutes. Lung retention of sulfuric-acid was determined. The effect of the acid mist on respiration was measured by means of a pneumotachograph. Lung retention of sulfuric-acid averaged 77 percent. Exposures to the lower concentrations of mist caused more shallow and more rapid breathing. The period of expiration was prolonged, averaging 69.3 percent of the breathing cycle versus 59.6 percent of the cycle when the subjects breathed air. At sulfuric-acid concentrations of 5mg/m3, the effects of the mist on respiration were more varied. The major response was a decrease in minute volume. The authors note that sulfuric-acid mists having concentrations below 3mg/m3 are not normally detectable. They conclude that respiratory changes induced by inhaling sulfuric-acid mists at concentrations on the order of 0.35mg/m3 are purely reflexive in nature. The more shallow, more rapid breathing may be a reflex protective mechanism to decrease the retention of acid mist particles.