Guidance

Timber treatment: application rates for single active ingredients

Published 5 February 2020

Applies to England

Householders and places of worship should call the national bat helpline on 0345 1300 228 before using a chemical product. It’s a free service for these groups.

Maximum application rates

Table 1. Maximum application rate in an undiluted product

Maximum application rate (ml per square metre) by concentration of a single active ingredient (%) in an undiluted product ^{[footnote 1]}.

Active Ingredient	0.02%	0.05%	0.1%	0.2%	0.4%	0.6%	0.8%	1%	5%	10%	50%
3-iodo-2-propynyl n-butylcarbamate	>5000	>5000	>5000	4140	2070	1380	1035	828	166	83	17
Benzalkonium chloride	4224	1690	845	422	211	141	106	84	17	8	2
Boric acid	>5000	>5000	>5000	>5000	>5000	4224	3168	2534	507	253	51
Copper carbonate hydroxide	>5000	>5000	>5000	3802	1901	1267	950	760	152	76	15
Dichlofluanid	>5000	>5000	>5000	>5000	>5000	4694	3520	2816	563	282	56
Disodium octaborate	>5000	>5000	2816	1408	704	469	352	282	56	28	6
Disodium octaborate tetrahydrate	>5000	>5000	>5000	>5000	2816	1877	1408	1126	225	113	23
Flufenoxuron	>5000	>5000	>5000	>5000	4224	2816	2112	1690	338	169	34
Permethrin	>5000	>5000	3672	1836	918	612	459	367	73	37	7
Propiconazole	>5000	>5000	>5000	4280	2140	1427	1070	856	171	86	17
Tebuconazole	>5000	>5000	>5000	4548	2274	1516	1137	910	182	91	18

Table 2. Maximum application rate in a product pre-diluted 5-fold

Maximum application rate (ml per square metre) by concentration of a single active ingredient (%) in a product that’s pre-diluted 5-fold with water ^{[footnote 1]}.

Active Ingredient	0.02%	0.05%	0.1%	0.2%	0.4%	0.6%	0.8%	1%	5%	10%	50%
3-iodo-2-propynyl n-butylcarbamate	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4140	828	414	83
Benzalkonium chloride	>5000	>5000	4224	2112	1056	704	528	422	84	42	8
Boric acid	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	2534	1267	253
Copper carbonate hydroxide	>5000	>5000	>5000	>5000	>5000	>5000	4752	3802	760	380	76
Dichlofluanid	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	2816	1408	282
Disodium octaborate	>5000	>5000	>5000	>5000	3520	2347	1760	1408	282	141	28
Disodium octaborate tetrahydrate	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	1126	563	113
Flufenoxuron	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	1690	845	169
Permethrin	>5000	>5000	>5000	>5000	4590	3060	2295	1836	367	184	37
Propiconazole	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4280	856	428	86
Tebuconazole	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4548	910	455	91

Table 3. Maximum application rate in a product pre-diluted 25-fold

Maximum application rate (ml per square metre) by concentration of a single active ingredient (%) in a product that’s pre-diluted 25-fold with water ^{[footnote 1]}

Active Ingredient	0.02%	0.05%	0.1%	0.2%	0.4%	0.6%	0.8%	1%	5%	10%	50%
3-iodo-2-propynyl n-butylcarbamate	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4140	2070	414
Benzalkonium chloride	>5000	>5000	>5000	>5000	>5000	3520	2640	2312	422	211	42
Boric acid	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	1267
Copper carbonate hydroxide	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	3802	1901	380
Dichlofluanid	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	1408
Disodium octaborate	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	1408	704	141
Disodium octaborate tetrahydrate	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	2816	563
Flufenoxuron	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4224	845
Permethrin	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	1836	918	184
Propiconazole	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4280	2140	428
Tebuconazole	>5000	>5000	>5000	>5000	>5000	>5000	>5000	>5000	4548	2274	455

Minimum application rates

Table 4. Minimum application rate in an undiluted product

Minimum application rate (square metres/litre) by concentration of a single active ingredient (%) in an undiluted product ^{[footnote 1]}

Active Ingredient	0.02%	0.05%	0.1%	0.2%	0.4%	0.6%	0.8%	1%	5%	10%	50%
3-iodo-2-propynyl n-butylcarbamate	<0.5	<0.5	<0.5	<0.5	<0.5	0.6	0.8	1.0	5.0	10.0	50.0
Benzalkonium chloride	<0.5	<0.5	<0.5	<0.5	<0.5	0.7	1.0	1.2	6.0	12.1	60.4
Boric acid	<0.5	0.6	1.2	2.4	4.7	7.1	9.5	11.8	59.2	118.4	591.8
Copper carbonate hydroxide	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	2.0	3.9	19.7
Dichlofluanid	<0.5	<0.5	<0.5	<0.5	<0.5	0.8	1.1	1.3	6.6	13.2	65.8
Disodium octaborate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.8	3.6	17.8
Disodium octaborate tetrahydrate	<0.5	<0.5	<0.5	0.7	1.4	2.1	2.8	3.6	17.8	35.5	177.6
Flufenoxuron	<0.5	<0.5	<0.5	<0.5	<0.5	0.5	0.7	0.9	4.4	8.9	44.4
Permethrin	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.6	3.0	5.9	29.6
Propiconazole	<0.5	<0.5	<0.5	0.5	1.1	1.6	2.2	2.7	13.6	27.2	136.2
Tebuconazole	<0.5	<0.5	<0.5	<0.5	<0.5	0.7	0.9	1.2	5.8	11.7	58.4

Table 5. Minimum application rate in a product pre-diluted 5-fold

Minimum application rate (square metres/litre) by concentration of a single active ingredient (%) in a product that’s pre-diluted 5-fold with water ^{[footnote 1]}

Active Ingredient	0.02%	0.05%	0.1%	0.2%	0.4%	0.6%	0.8%	1%	5%	10%	50%
3-iodo-2-propynyl n-butylcarbamate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.2	2.4	12.1
Benzalkonium chloride	<0.5	<0.5	<0.5	<0.5	0.9	1.4	1.9	2.4	11.8	23.7	118.4
Boric acid	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.8	3.9
Copper carbonate hydroxide	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.3	2.6	13.2
Dichlofluanid	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.7	3.6
Disodium octaborate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.6	0.7	3.6	7.1	35.5
Disodium octaborate tetrahydrate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.9	1.8	8.9
Flufenoxuron	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.6	1.2	5.9
Permethrin	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.5	2.7	5.4	27.2
Propiconazole	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.2	2.3	11.7
Tebuconazole	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.1	2.2	11.0

Table 6. Minimum application rate in a product pre-diluted 25-fold

Minimum application rate (square metres/litre) by concentration of a single active ingredient (%) in a product that’s pre-diluted 25-fold with water ^{[footnote 1]}

Active Ingredient	0.02%	0.05%	0.1%	0.2%	0.4%	0.6%	0.8%	1%	5%	10%	50%
3-iodo-2-propynyl n-butylcarbamate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	2.4
Benzalkonium chloride	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	2.4	4.7	23.7
Boric acid	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.8
Copper carbonate hydroxide	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.5	2.6
Dichlofluanid	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.7
Disodium octaborate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.7	1.4	7.1
Disodium octaborate tetrahydrate	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.8
Flufenoxuron	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	1.2
Permethrin	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.5	1.1	5.4
Propiconazole	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	2.3
Tebuconazole	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	2.2

Median lethal dose, LD₅₀

The dose of single active ingredients required to kill 50% of a tested population after a specified test duration.

Active ingredient	LD50 (mg/kg body mass)
3-iodo-2-propynyl n-butylcarbamate	1470
Benzalkonium chloride	150
Boric acid	4500
Copper carbonate hydroxide	1350
Dichlofluanid	5000
Disodium octaborate	500
Disodium octaborate tetrahydrate	2000
Flufenoxuron	3000
Permethrin	652
Propiconazole	1520
Tebuconazole	1615

1. The relationship between application rate and the concentration of active ingredient is linear. The application rate can be interpolated for a concentration that falls between values listed. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶