Sawmill workers should be careful when using anti-sapstain chemicals on the job Part IV in a series by Shona Kelly Research Scientist University of British Columbia In this final article in a four part series I list the most commonly used anti-sapstain products and provide information on their known effects. First, let me dispose of a myth. Chlorophenols, the anti-sapstain pesticides used in the past, were not removed from the market because they were hazardous to humans. They were removed from the market because they are hazardous to the envrion- ment (for example they can accumulate in shell- fish). Anti-sapstain chemicals wash out of the sawmill yard with every rainfall. Environmental testing is an important component of current gov- ernment registration processes. For example TCMTB is much kinder to the environment than were the chlorophenols. At the time the chlorophenols were removed from the market few sawmills used any other prod- ucts. The market is now ‘wide open’ and a great number of products are in various stages of regis- tration with Agriculture Canada. The table below lists all the products thought to be under review at Agriculture Canada. It may not be complete. The first attempts to introduce these alternative anti-sapstain products were, to understate the prob- lem, difficult. Most sawmill workers did not regard chlorophenols as particularly hazardous and since they did not irritate the skin, eyes or nose little attempt was made to avoid exposure. But . . . the new products are irritants and the first product introduced, TCMTB, is a severe skin irritant. It is not a good idea to crawl inside an operating spray box to fix a spray nozzle when TCMTB is being used! The pesticide manufacturers were flabber- gasted at the casual attitude taken by sawmill work- ers and had to be reminded that chlorophenols didn’t cause these symptoms. Sawmill workers needed to learn, and I think they have, to treat these pesticides with respect. It has been an enormous learning experience on all sides. Since most of these pesticides are irritants it is important to avoid contact with them in any form. The most effective and comfortable way to avoid mist from the spray boxes is to construct/altar the spray boxes to reduce spray drift. It is not possible to grade or sort lumber while wearing a respirator. All workers exposed to the treated wood should wear protective clothing. Leather and cloth are not protective; they absorb the pesticide and keep it in constant contact with your skin. Depending upon your working style and job, you may require a chemical-resistant apron, chemical-resistant gloves and chemical-resistant boots. A good safety supply = ¢ Dressed in protective coveralls, with protective gloves and respirator cartridge mask, millwright Gil Davis, safety chairman at Interfor’s Western Whitewood division in New Westminster, cleans out nozzle in sapstain rebuilding area. company can advise you on what material will pro- vide protection from these chemicals. Maintenance workers have the potential for exposure as well and protective equipment should be worn when work- ing around the spray delivery system, the spray box or the mill equipment downstream from the spray process. In the following boxes I describe the various active ingredients listed in the table. Most are SKIN OR EYE IRRITANTS. It is not possible to go back to the old, wasteful and unhealthy practices of the past. No more drive-through diptanks, open spray boxes or unprotected pullers. PRODUCT MANUFACTURER INGREDIENTS Ap-143 Chapman Azaconazole & IPBC. Bardac 22 Lonza DDAC Bardac 2250 Lonza DDAC Bardac 2280 Lonza DDAC Bravo ISK- Biotech. Chlorothalonil Busan 30WB Buckman TCMTB Busan 1030 Buckman TCMTB Chapco SA-1 Kop-Coat Inc DDAC & IPBC_ Daconil Flowable Fungicide ISK-Biotech Chlorothanlonil Daconil Fungicide ISK-Biotech Chlorothanlonil : Defence Anti Stain Hoechst Azaconazole & Carbendazim Ecobrite C Diachem Industries Borax & Sodium Carbonate Ecobrite Diachem Industries Borax & Sodium Carbonate F2 Walker Brothers DDAC & Borax Mitrol PQ-8 Chapman Copper-8-Quinolate NP-1 Kop-Coat Inc DDAC & IPBC Nytek GD Maag Copper-8-Quinolate PQ-57 Chapman Copper One fanssen conazole ee 300 SOTU er Azaconazole & Chlorothalonil Sta-Brite A Chapman Azaconazole & IPBC Sta-Brite A Chapman IPBC Sta-Brite P Chapman IPBC : Technical Grade ISK-Biotech Chlorothalonil Timbercote 2000 Kop-Coat Inc DDAC & IPBC Troysan Polyphase AF-1 Troysan IPBC ‘Troysan Polyphase P-100 Troysan IPBC Woodgard E.C. Sadolin IPBC Xylophene Xylochemie Azaconazole FE TTF Be, AZACONAZOLE 4 rade names: Rodewod 200EC, Xylophene Tab Acute effects: Oral LD50: 217-540 mg/kg; 1291 mg/kg (Rodewod 200EC); >2000 mg/kg (Xylophene Tab 2) Dermal LD50: >3100 mg/kg; 2190 mg/kg Cae 200EC); 4000 mg/kg (Xylophene Tal LC50: >0.06 mg/L (5% in water); 1.48 mg/L (Rodewod 200EC) Irritation and Sensitization: the active ingredient is non-irritating to eyes, a slight skin irritant but not a sensitizer. Xylophene Tab 2 is described as corrosive. The manufac- turer describes Xylophene Tab 2 as “highly toxic if inhaled”. Chronic effects: Mutagenicity: negative in all tests to date Carcinogenicity: no evidence in rats fed up to 800 ppm. Effects on Reproduction: no evidence of effects. The no-observable-effect-level for birth defects set 60 mg/kg/day BORAX Trade names: Ecobrite, Ecobrite C Acute effects: Oral LD50: >3000 mg/kg Dermal LD50: no information available LC50: no information available Irritation and Sensitization: moderately irritating to eyes but non irritation to skin. There is no information on sensitization Chronic effects: Mutagenicity: no mutagenic effects in ublished reports ® Cateinageatese no indication of carcino- enicity in publi reports 5 ea ae Reproduction: no effects reported in published reports 10/LUMBERWORKER/OCTOBER, 1992