Ashes (residues), nonhazardous municipal solid waste

Surface tension

Administrative data

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18.2.2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

no

GLP compliance:

yes

Type of method:

OECD harmonised ring method

Test material

Test material information

Constituent 1

Reference substance name:

Ashes (residues)

EC Number:

268-627-4

EC Name:

Ashes (residues)

Cas Number:

68131-74-8

Test material form:

solid: bulk

Details on test material:

- Name of test material (as cited in study report): Ashes (residues)
- Substance type: technical product
- Physical state: solid
- Main components: SiO2 (42.12%), Al2O3 (32.16%), Fe2O3 (10.88%), TiO2, MnO, MgO, CaO, Na2O, K2O, SO3 - constituents with content less than 10%
- Expiration date of the lot/batch: unlimited
- Appearance: greyish black powder

Results and discussion

Surface tension

Surface tension:

69.4 mN/m

Temp.:

20 °C

Conc.:

1 g/L

Any other information on results incl. tables

Measured values

Results of the time dependence of the measured surface tension values of the test substance are given in the following table.

 

Table No. 1 Results of the surface tensionmeasurement (bold: equilibrium state)

Time (min)	0	5	10	15	20	25	30	35	40	45
P (dyn/cm)	74.3	74.4	74.3	74.3	74.2	74.2	74.3	74.2	74.2	74.2

 

After en equilibrium state had been achieved, an arithmetic average was calculated from values measured in the equilibrium state. Theresult (74.2 dyn/cm) was used for other calculations.

Calculation

The calculation was carried out according toformula, which is given in the manual of measuring instrument:

 

F = 0.7250 + [0.01452*P*C^-2*(D-d)^-1+ 0.04534 – 1.679*r*R^-1]^1/2

 

where 

 

F = the correction factor

R = the radius of the ring

r = the radius of the wire of the ring

P = the apparent value of surface tension in mN/m

D = the density of the lower phase (used density of water at 20°C)

d = the density of the upper phase (used density of air at 20°C)

C = the circumference of the ring

 

F = 0.7250+[0.01452*74.2*5.935^-2*(0.99821-0.00120)^-1+0.04534 – 1.679*53.1666358^-1]^1/2

 

F = 0.935804

 

S = P . F = 74.2 * 0.935804 = 69.4 dyn/cm = 69.4 mN/m

Applicant's summary and conclusion

Conclusions:

The test substance, Ashes (residues), at apparent test concentration of 1 g/L shows corrected surface tension of 69.4 mN/m at 20°C (± 0.5 °C). As the surface tension is higher than 60 mN/m, test substance should not be regarded as a surface-active material.

Executive summary:

The surface tension of the test substance, Ashes (residues), was measured.

 

The study was performed according to the Method A.5 Surface tension, Directive 92/69/EEC, published in OJ No L 383 A, December 1992, using theOECD harmonized ring method for the measurement (Part 1.6.4.).

 

The test substance was dissolved in distilled water and filled up to a volume of 250 mL (if the whole amount of the test substance was dissolved, the concentration would be equal to 1 g/L - the highest concentration that can be used). Surface tension was measured by ring method with Surface tensiometer, type 20 (Cole Parmer). The testing was performed at 20°C(± 0.5 °C).

 

The test substance, Ashes (residues), at apparent testconcentration of 1 g/L shows corrected surface tension of 69.4 mN/m at 20°C(± 0.5 °C). As the surface tension is higher than 60 mN/m, test substance should not be regarded as a surface-active material.