Registration Dossier

Administrative data

Endpoint:
pH
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data accepted by a national regulatory agency

Data source

Reference
Reference Type:
publication
Title:
Bromine Final Registration Review Decision Case 4015
Author:
US Environmental Protection Agency OPPTS
Year:
2010
Bibliographic source:
US EPA Prevention, Pesticides, and Toxic Substances, Docket number EPA-HQ-OPP-2009-0167
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EPA OPPTS 830.7000 (pH)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Bromine
- Analytical purity: Technical Grade Active Ingredient 98-100%

Results and discussion

Any other information on results incl. tables

Tap water has the capacity to buffer the effect on pH by the addition of bromine.

Bromine, mg/L

pH value

0

7.2

2.5

7.2

16.3

7.2

29.2

7.3

When bromine is added to deionized water, bromine reduces the pH since hypobromous acid, a weak acid, is formed. Deionized water has no buffer capacity so the pH of the solution decreases. 

Bromine, mg/L

pH value

0

5.6

1.0

5.3

11.0

4.1

19.4

3.8

50.0

3.4

Applicant's summary and conclusion

Conclusions:
The effect of bromine on pH of aqueous solutions depends on the type of water used for dilution. Tap water has buffering capacity, so that little change is seen in pH from that of the control solution. (0% bromine pH 7.2 vs 29.2 mg/l bromine pH 7.3) Deionized water lacks the buffering capacity, and the pH of the solution decreases as hypobromous acid, a weak acid, is formed. (0% bromine pH 5.6 vs 50.0 mg/L bromine pH 3.4).
Executive summary:

The effect of bromine on pH of aqueous solutions depends on the type of water used for dilution. Tap water has buffering capacity, so that little change is seen in pH from that of the control solution. (0% bromine pH 7.2 vs 29.2 mg/l bromine pH 7.3) Deionized water lacks the buffering capacity, and the pH of the solution decreases as hypobromous acid, a weak acid, is formed. (0% bromine pH 5.6 vs 50.0 mg/L bromine pH 3.4).