Boric acid

Additional physico-chemical information

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

other: Corrosivity to metals

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-05-21 - 2010-05-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: UN Transport of Dangerous Goods Recommendations, Fourth Revised Edition (Class 8, Packing 8, Packing group III, test C1).

Deviations:

not specified

GLP compliance:

yes

Results:

Steel coupons:
No reaction was observed on submersion of the coupons. On completion of the test some crystallisation was observed on the vessel and on the vapour surface coupons. Rust deposits were observed on all coupons with no significant localised corrosion observed. On completion of the test the sample was observed to be an orange/brown liquid with orange/brown deposits at the bottom of the vessel.
The highest percentage mass loss (over 7 days) on the steel coupons was found to be 2.10 %.

Aluminium coupons:
No reaction was observed on submersion of the coupons. On completion of the test some crystallisation was observed on the vessel and on the vapour surface coupons. Localised corrosion was observed on the submersed coupons. On completion of the test, the sample was observed to contain crystalised solids on the surface.
The highest percentage mass loss (over 7 days) on the aluminium coupons was found to be 1.56 %. The depth of the deepest intructions observed on aluminium coupon numbers 3, 6 and 9 (fully submersed) were also measured and the depths found to be 72 μm, 154 μm and 80 μm respectively.

The percentage mass losses on steel and aluminium were found to be < 13.5 % over 7 days, however the maximum pit depth on the aluminium coupons was > 120 μm. The saturated solution of boric acid was therefore a candidate for classification as a corrosive substance of UN Class 8, Packing group III ( according to the UN Transport of Dangerous Goods Recommendations).

Test results for steel coupons:

Coupon no.	Position of coupon	Initial mass (g)	Final mass (g)	Weight loss (g)	Percentage mass loss (%)
1	Vapour space	15.5737	15.5463	0.0274	0.18
2	Half submerged	15.5848	15.3705	0.2143	1.38
3	Fully submerged	15.4493	15.1422	0.3071	1.99
4	Vapour space	15.5197	15.4997	0.02	0.13
5	Half submerged	15.6282	15.4199	0.02083	1.33
6	Fully submerged	15.5231	15.2221	0.301	1.94
7	Vapour space	15.6317	15.6003	0.0314	0.20
8	Half submerged	15.5838	15.3218	0.262	1.68
9	Fully submerged	15.6516	15.3236	0.328	2.10

Test results for aluminium coupons:

Coupon no.	Position of coupon	Initial mass (g)	Final mass (g)	Weight loss (g)	Percentage mass loss (%)
1	Vapour space	5.7010	5.7005	0.0005	0.01
2	Half submerged	5.7485	5.7392	0.0093	0.16
3	Fully submerged	5.7217	5.7162	0.0055	0.10
4	Vapour space	5.7718	5.7709	0.0009	0.02
5	Half submerged	5.7141	5.7102	0.0039	0.07
6	Fully submerged	5.350	5.7284	0.0066	0.12
7	Vapour space	5.7640	5.6742	0.0898	1.56
8	Half submerged	5.7754	5.7666	0.0088	0.15
9	Fully submerged	5.7655	5.7517	0.0138	0.24

Conclusions:

The percentage mass losses on steel and aluminium were found to be < 13.5 % over 7 days, however the maximum pit depth on the aluminium coupons was > 120 μm. The saturated solution of boric acid was therefore a candidate for classification as a corrosive substance of UN Class 8, Packing group III (according to the UN Transport of Dangerous Goods Recommendations).

Executive summary:

Corrosivity to metal of the test-item was assessed in a GLP-study according to UN Transport of Dangerous Goods Recommendations, Fourth Revised Edition (Class 8, Packing 8, Packing group III, test C1).

The percentage mass losses on steel and aluminium were found  to be < 13.5 % over 7 days, however the maximum pit depth on the aluminium coupons was > 120 μm.  The saturated solution of the sample was therefore a candidate for classification as a corrosive substance of UN Class 8, Packing group III (according to the UN Transport of Dangerous Goods Recommendations).

Reference 2

Endpoint:

other: Explosivity of dust cloud

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: No data

Deviations:

not specified

Principles of method if other than guideline:

A spatula test and an ignition tube test were used to assess the flammability of a dust cloud.

GLP compliance:

yes

Results:

Spatula test result:
The sample melted to a clear liquid emitting small quantity of grey smoke, which ignited with a small green, nonsustaining flame. On completion of testing a white material remained.

Ignition tube result:
The sample melted to a clear liquid emitting small quantity of grey smoke, which ignited with a small green, nonsustaining flame. On completion of testing a white material remained.

Conclusions:

In both the spatula test and the ignition tube test the sample melted to a clear liquid emitting small quantity of grey smoke, which ignited with a small green, non-sustaining flame. On completion of testing a white material remained.

Executive summary:

A spatula test and an ignition tube test were used to assess the flammability of a dust cloud of the test item in a GLP-study.

In both the spatula test and the ignition tube test the sample melted to a clear liquid emitting small quantity of grey smoke, which ignited with a small green, non-sustaining flame. On completion of testing a white material remained.

Reference 3

Endpoint:

other: Emisison of flammable gas when in contact with water.

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-6-04 - 2010-06-07

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: UN Recommendation on the Transportation of Dangerous Goods, Manual of Tests and Criteria for substances of Class 4, Division 4.3.

Deviations:

not specified

GLP compliance:

yes

Results:

It was determined that the test sample is not classified as a material of class 4.3. The gas was not tested for flammability.

Test results:

Run	Powder quantity (g)	Max rate of gas generation (L.hr-1.kg-1)	Ignition/no ignition
1	10	0.14	No ignition
2	25	0.11	No ignition
3	25	0.05	No ignition

Conclusions:

It was determined that the test item should be classified as not a material of Class 4.3 according to the UN recommendations on the Transportation of Dangerous Goods

Executive summary:

The test sample was assessed in a GLP study according to UN Recommendation on the Transportation of Dangerous Goods, Manual of Tests and Criteria for substances of Class 4, Division 4.3 if the test item emits flammable gases when it comes in contact with water. It was determined that the test sample is not classified as a material of class 4.3. The gas was not tested for flammability.

Reference 4

Endpoint:

other: Dustiness

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-06-26 - 2010-07-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: CIPAC method MT 171

Deviations:

not specified

GLP compliance:

yes

Results:

The results showed that boric acid granular did not produce significant amounts of dust and was nearly dust free. Boric acid powder did produce a significant amount of dust and was classified as dusty.

Dustiness:

Test item	Batch/ Reference No.	Weight of filter disk before dust collection (mg)	Weight of filter disk after dust collection (mg)	Weight of dust collected	Dust category	Assessment of dustiness
Boric acid (tech grade granular)	N/A	59.9	60.9	1.0	1	Nearly dust free
Boric acid (powder)*	4270	57.7	135.8	78.1	3	Dusty
	4270	60.9	150.1	89.2	3	Dusty

*For the boric acid powder the analysis was carried out in duplicate as there was enough sample for more than one determination. The second result was based on a sample weight of less than 30 g (28.4081 g) but both results fall into the dust category 3 which is dusty.

Conclusions:

The dustiness of boric acid granular (d50 mm 0.608) and boric acid powder (d50 mm 0.051) were assessed according to CIPAC method MT 171. Boric acid granular did not produce significant amounts of dust and was nearly dust free. Boric acid powder did produce a significant amount of dust and was classified as dusty.

Executive summary:

The dustiness of boric acid granular (d50 mm 0.608) and boric acid powder (d50 mm 0.051) were assessed according to CIPAC method MT 171 in a GLP-study. Boric acid granular did not produce significant amounts of dust and was nearly dust free. Boric acid powder did produce a significant amount of dust and was classified as dusty.

Reference 5

Endpoint:

other: Dustiness

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2010-06-26 - 2010-07-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: CIPAC Method MT 171

Deviations:

not specified

GLP compliance:

yes

Results:

The results showed that boric acid TP with a particle size (d50) of 119 μm did produce some dust but was essentially non-dusty.

Dustiness:

Test item	Weight of filter disk before dust collection (mg)	Weight of filter disk after dust collection (mg)	Weight of dust collected	Dust category	Assessment of dustiness
Boric acid (Boric acid TP)	54.2	69.4	15.2	2	Essentially non-dusty

Conclusions:

Boric acid TP was assessed for dustiness according to CIPAC method MT 171. Boric acid TP (d 50 119 μm) did produce some dust but was essentially non-dusty.

Executive summary:

Boric acid TP was assessed for dustiness according to CIPAC method MT 171 in a GLP-study. Boric acid TP (d 50 119 μm) did produce some dust but was essentially non-dusty.

Description of key information

GLP-Studies were performed according to UN Transport of Dangerous Goods Recommendations, Fourth Revised Edition (Class 8, Packing 8, Packing group III, test C1) on corrosivity to metals; and according to UN Recommendation on the Transportation of Dangerous Goods, Manual of Tests and Criteria for substances of Class 4, Division 4.3, on the emission of flammable gases on contact with water were conducted. The percentage mass losses on steel and aluminium were found  to be < 13.5 % over 7 days, however the maximum pit depth on the aluminium coupns was > 120 μm.  The saturated solution of boric acid was therefore a candidate for classification as a corrosive substance of UN Class 8, Packing group III ( according to the UN Transport of Dangerous Goods Recommendations). It was determined that the test sample is not classified as a material of class 4.3. The gas was not tested for flammability.

GLP-Studies on dustiness were performed according to CIPAC method MT 171 and showed that boric acid granular was dust category 1 - nearly dust free; boric acid TP was dust category 2 - essentially non-dusty and boric acid powder was dust category 3 - dusty. This sample represents the finest grade placed on the market.

The dust explosion behaviour was also assessed in a GLP study. A spatula test and an ignition tube test were used to assess the flammability of a dust cloud of the test item.

In both the spatula test and the ignition tube test the sample melted to a clear liquid emitting small quantity of grey smoke, which ignited with a small green, non-sustaining flame. On completion of testing a white material remained.