S.I. No. 286/1952:

STANDARD SPECIFICATION (COAL TAR CREOSOTE FOR THE PRESERVATION OF TIMBER) ORDER, 1952.

STANDARD SPECIFICATION (COAL TAR CREOSOTE FOR THE PRESERVATION OF TIMBER) ORDER, 1952.

I, SEAN F. LEMASS, Minister for Industry and Commerce, in exercise of the power conferred on me by subsection (3) of section 20 of the Industrial Research and Standards Act, 1946 (No 25 of 1946), hereby order as follows :--

1. This Order may be cited as the Standard Specification (Coal Tar Creosote for the Preservation of Timber) Order, 1952.

2.--(1) The specification set forth in Part II of the Schedule to this Order is hereby declared to be the standard specification for the commodity described in Part I of the said Schedule.

(2) The said standard specification may be cited as Irish Standard 43 : 1952.

SCHEDULE.

PART I.

COAL TAR CREOSOTE FOR THE PRESERVATION OF TIMBER.

PART II.

SPECIFICATION.

In this specification, the letters B.S., when followed by two sets of numbers, refer to the British Standard of which the first is the serial number and the second is the year of its publication by the British Standards Institution.

SCOPE.

1. This specification covers the requirements of coal tar creosote for the preservation of timber.

SPECIFIC GRAVITY.

2. The specific gravity of the creosote at 38°C., when determined with a specific gravity bottle, shall be not lower than 1·010 and not higher than 1·065 with reference to the specific gravity of water at 20°C.

FLUIDITY.

3. The creosote shall be completely fluid when heated to 38°C. and shall remain fluid on standing for two hours at 32°C.

WATER CONTENT.

4. The creosote, when tested in the manner described in Appendix A, shall not contain more than 3·0 per cent. of water by volume.

DISTILLATION.

5. The percentage distillate by weight, when determined on a water free basis as described in Appendix B, shall be not more than :

6 per cent. at 205°C.

40 per cent. at 230°C.

78 per cent. at 315°C.

RESIDUE AFTER DISTILLATION.

6. The residue after distillation at 315°C. shall be soft but not sticky.

TAR ACIDS.

7. The content of tar acids, when determined as described in Appendix C, shall be not less than 5 per cent. and not more than 16 per cent. by weight.

MATTER INSOLUBLE IN BENZENE.

8. The percentage by weight of the creosote insoluble in benzene, when determined as described in Appendix D, shall not exceed 0·4.

SAMPLING AND SIZE OF SAMPLE.

9. For the purpose of testing conformity with the requirements of this specification a representative sample measuring not less than 1 gallon shall be taken from the bulk. The sample shall be packed in a clean, dry, air-tight container made of material on which the sample has no action. A rubber stopper shall not be used for closing the container. The container shall be sealed and shall be marked with the date of sampling and with sufficient information to identify the sample. Wax, pitch, or similar compositions, if used for sealing the container, shall be employed in such a way that when the container is opened the contents are not contaminated by the material of the seal.

Appendix A.

DETERMINATION OF WATER CONTENT.

The apparatus required for this determination shall consist of a glass retort, a condenser, a Bunsen burner with a rose attached, and a Crow receiver conforming to B.S. 605 : 1935. The retort shall be of capacity suitable for the distillation of 250 ml. of material. The condenser shall consist of a straight glass tube 600 mm. ± 10 mm, long and of sufficient bore to allow of its being fitted by means of a cork to the delivery end of the retort. The glass tube of a Liebig condenser may be used provided that the junction of the wide and narrow portions is drawn out in such a way as to eliminate any sharp angle where distillate may lodge.

The sample shall be maintained at a temperature of 38°C. and constantly stirred until it becomes completely fluid. The sample shall then be well shaken and 250 ml. poured into the retort. Distillation shall be commenced and continued until water ceases to drip into the receiver. During the distillation the retort shall be covered with a metallic or asbestos hood to prevent undue condensation of water in the upper part. If any solidified hydrocarbons should appear in the condenser they shall be melted by gentle heating and allowed to drain into the receiver. Any water which adheres to the condenser shall be driven into the receiver in a similar manner.

The receiver shall be placed in a steam oven until the contents are completely fluid, allowed to cool to 38°C. and the volume of water noted. This volume in millilitres multiplied by 0·4 shall be taken as the percentage of water in the creosote.

Appendix B.

METHOD OF DISTILLATION.

The apparatus to be used shall be a distillation flask of 150 ml. capacity conforming to B.S. 571 : 1934, an air condenser conforming to Type 3 of B.S. 658 : 1936, a draught screen conforming to B.S. 658 : 1936 with the shelf removed, a Bunsen burner, three small tared glass flasks and a thermometer of the type specified below. The thermometer shall be fitted to the flask so that the bottom of the capillary is level with the lower edge of the side tube.

The creosote oil which remains in the retort after the determination of water content as described in Appendix A shall be allowed to cool to 38°C. and shall be mixed with any oil which distilled over in the same determination. One hundred g. of the mixture shall be weighed at 38°C. and shall be placed in the distillation flask. At the commencement of the distillation the naked flame of the burner shall be used. The heating of the flask shall be regulated so that 4 to 5 ml. of oil is distilled per minute. The receiver shall be changed at each specified temperature without stopping the distillation but the final fraction shall include all oil which drains from the condenser after the flame has been extinguished. The condenser shall be kept free from solidified hydrocarbons throughout the distillation by the application of just sufficient heat.

All the temperatures specified for the distillation shall be corrected for the variation of the actual barometric pressure P, from the pressure of 760 mm. by adding to the temperatures the value of C as calculated by the formula :

C=0·06(P--760).

The thermometer used in this determination shall cover the range 90°C. to 400°C. with 1° graduations. It shall conform to the requirements for Standard Thermometer No. T 4c prescribed in " Standard Methods for Testing Tar and its Products," pp. 346-349, third edition (1950), published by Standardization of Tar Products Tests Committee, 166 Piccadilly, London, W.1, England. A copy of this publication is available for reference in the library of the Institute for Industrial Research and Standards, Dublin.

The thermometer shall be verified as correct at intervals not greater than 5 years by the Institute for Industrial Research and Standards.

Appendix C.

DETERMINATION OF TAR ACIDS.

The fraction obtained on distilling below 315°C. in the determination described in Appendix B shall be liquefied by warming and poured into a 250 ml. glass flask. Any oil adhering to the receivers in which the distillates were collected shall be rinsed into the flask with 25 ml. of 10 per cent. aqueous sodium hydroxide solution at 40°C. to 70°C. The sodium hydroxide solution shall then be shaken vigorously for 5 minutes with the oil in the flask.

The mixture shall be transferred to a separating funnel and, after settling, the lower layer shall be run into a conical flask. The oil shall then be agitated for 5 minutes with 25 ml. of a sodium hydroxide solution similar to that described above and the lower layer run into a conical flask. This procedure shall be repeated until all the tar acids have been removed. The temperature of the oil during the washing shall be sufficiently high to prevent deposition of solids.

The separate extracts shall be combined and boiled for 10 minutes or until the odours of tar oils and bases have disappeared. Fragments of porous material may be used to prevent bumping.

The solution shall be cooled to room temperature and poured into a 200 ml. flask with a 25 ml. scale on the neck. The flask shall conform to B.S. 676 : 1936. Sufficient concentrated hydrochloric acid shall be added to acidify the solution using methyl orange as indicator. The material shall appear to be acid after vigorously shaking together the two layers.

The aqueous layer shall be saturated by adding 25 g. of powdered sodium chloride and the tar acids shall be brought into the graduated neck of the flask by adding saturated salt solution.

The material shall be allowed to settle for an adequate time and the volume in millilitres of tar acids shall be read and shall be taken as the content of tar acids.

Appendix D.

DETERMINATION OF MATTER INSOLUBLE IN BENZENE.

The sample of creosote shall be well mixed and 50 g. weighed and placed in a conical flask. The creosote shall be dissolved in four times its volume of benzene, by warming the flask on a water bath, the flask being loosely covered. The benzene used shall conform to the requirements for 90's benzole specified in B.S. 135 : 1939.

The solution shall be filtered through a weighed sintered glass filtering crucible, previously dried at 100°C. Alternatively, two tared filter papers about 150 mm. in diameter and of equal weight may be used, the papers after folding being placed one within the other. Any insoluble residue shall be transferred to the filter by the addition of more benzene and the filter washed with benzene until a few drops of the filtrate yield no residue on evaporation.

The residue shall be dried at 100°C., allowed to cool in a desiccato and weighed. This process shall be repeated until the weight is found to be constant. This constant weight, multiplied by 2, shall be taken as the percentage of the creosote insoluble in benzene.

GIVEN under my Official Seal this 22nd day of September, 1952.

SEÁN F. LEMASS,

Minister for Industry and Commerce