Document LpyrNx79YoQGj2GG6qbV11Vjq

FILE NAME: Phenolic Resins (PHR) DATE: 1974 June 12 DOC#: PHR053 DOCUMENT DESCRIPTION: Letter from Gillette to CPSC RE Request for Info; from Hair Dryer File Jo*Mt tob*<l lo o* June 12, 1974 F /f< /9 7~L- Th* GUUtt# Company * *-- -t- - -- > --- JB7JiTWt05 Mr. Carl Blechachmidt Director, Division of Product Defect Identification Consumer Product Safety Commission Room 202 5401 Westbard Avenue Washington, D. C. 20207 Re: CPSC 15P - 129 CPSC 15P - 130 Dear Mr. Blechachmidt: This ' etter Is In response to your above-referenced requests for Information regarding The Gillette Company' s Max hair dryer THD-2 and Super Max hair dryer HD-7, As I noted to Mr. Kltzes of your office In a telephone conversa tion on May 29, 1974, Gillette recently moved its Appliance Division from Chicago to Boston; vour m ailgram s were forwarded to us from Chicago and were received on May 29, 1974. This letter will discuss the Issu es you raised with regard to the THD-2 and HD-7 and supply you with the information you requested with respect thereto. Evaluation of Possible Risk . In your mailgrams you suggest that the heating colls in the THD-2 and HD-7 might short circuit. In order to evaluate the risk. If any, which 3uch short circuiting might present, it Is necessary to consider the possible consequences thereof. Short c.rcuits in the heating coils produce arcir.g--n in ute, momentary electrical d is. .a ru c s. Arcir.g Is to be distinguished from sparking: the latter exist. on!v wr. .re ir.candcsccr.t matter Is expeiled. The arcing caused by hearing coll short circuits is the sam e sort of brief electrical discharge one gets when plugr.r.g it. ar.v hojsehc'.J appliance. The cr'.v I f near hr fl 2 r : side the unit rcinr could conceivably lead is the igniting of h could only happen if the arcing occurred out:lv no standard test to evaluate this sort of risk; CONFIDENTIAL G 00414  4 '* " C arl Blechschm June 12. 1974 Page 2 . v r- -V - " - " It Is our understanding that Underwriters' Laboratories, Inc. Is currently working to devise such a test. In lieu of any standard test, we attem pted Ignite two highly flammable fabrics by means of the arcing from 14 HD-7 dryers which had exhibited coll shorts In a previous test.' (In that sam e test, no THD-2s had exhibited arcing outside the unit, which means that the likelihood of Ignition of flammable m aterials Is extremely low.) The m aterials chosen were surgical cotton and cheesecloth. These are among the most highly flammable of fabrics am. are or will be used by Underwriters' Laboratories in ordinary flammability hazard testing. In the test, half of the HD-7s were wrapped In surgical cotton and half in cheesecloth. The exhaust grille on each dryer was removed to allow a s much arcing a s possible to contact the material (m ost arcin g occurs Inside the dryer - In only two out of eighty HD*7s examined in a previous test was there arcing outside the unit). A total of over 400 coll shorts were then generated by impacting the units. * In no Instance did the flammable m aterial Ignite, scorch or discolor. In our opinion, such arcing as Is generated by Impact cannot ignite highly flammable m aterials, is not capable of causing any other damage'and cannot be considered hazardous. You suggest In your mall gram relating to the HD-7 that the plastic casing might burn. All HD-7 cases are made of polycarbonate, a m aterial with excellent impact resistance ch aracteristics. This plastic Is not flammable In the sense that paper is flammable. It will not sustain combustion after being subjected to the d *TM * from a match or a 30 second application of the flame from a butane cigarette lighter. ' Application of hotter and/or more prolonged flames will result in burning of the plastic, but even this will gradually self-extbguish: the case material Is classified a s self-extinguishing by Underwriters' Laboratories. Apart from these ch aracteristics of the p lastic casing, all dryers made for the Appliance Division contain various structural safety features. There Is, for instance, a thermostat which prevents the build-up of intense heat. One hundred percent of these are Inspected twice during production. Furthermore, the possible sources ot ignition in the HD-7 are Insulated from the plastic casing by heat-resistant m aterials. Fo r example, the heater box containing the co d s Is made from high density, heat resist phenolic. The open ends of the heater box are shielded by a screen and phenolic grn.e on one end and an aluminum fan on the ocher. We conclude that, although the plastic casLng of the HD-7 can be made to burn, such vnirrn-rc Is extremely unllkelv In actual use and Ir. no case could be causes by Injury to users of the HD-7. Wc have prc-iouslv furnished the Cor.su sumcr complaint data for 19/3 regardin G 00415 r I ->> IV'.C;.'. P r ! Blechschmldt June 12, 197-1 Page 3 by the Appliance Division of The Gillette Company. In the present letter we would like to particularize this information for the THD-2 and HD-7, update to include available 1974 data and offer further information. ' W.e classify certain of our consumer correspondence as "non-routine".complaints. These include Instances where the consumer complained of personal injury (burned or singed hair, other hair damage, shock, burned skin) or property damage, or where our tests confirmed a serious product defect (thermostat failure, failure of dielectric test, actual signs of Intense heat). It should be emphasized that, since almost ill consumers are satisfied with repair o r replacement of their dryer, com plaints of personal injury or property damage a re not in fact verified. In 1973 the Appliance Division received a total of ten non-routlna complaints on the THD-2. This represents . 0006% of the number of THD-2 dryers estimated to be In the hands of consum ers in 1973. One of the ten units was not returned,- two were not examined (replacement of units under warranty), and three files have been m is placed following the Division's move to Boston. Three of the remaining four were found to have component defects or malfunctions unrelated to the possible heating coll defect referred to in your mail gram . The remaining mlt; exhibited a short circuit which may have been caused by beating coil shorting. Consumer complaints oo the THD-2 for 1973 can be summarized a s follows: four persons complained of burned or singed h a ir, three of shock, two of fire ; flame or smokej and one of property damage. ` In 1973, three aon-routlne complaints were received on the HD-7, which represents .0003% of the number of units estim ated to be in the hands of consumers in 1973. In two cases no apparenc malfunction was discovered; one unit was not returned. Two persons complained of burned skin anri one of shock. For the first four months of 1974, the Appliance Division received 14 non-routine complaints on the THD-2; this represents .0008% of-the number of dryers estim ated to be In the hands of consumers as of April 30, 1974. Eleven of the units Lnvoh-ed were returned and examined; of these, eight were found to contain component defects or malfunctions unrelated to coil shorting. Three of the remaining units had unspeci fled heating coil malfunctions (not necessarily short circuiting due to the mounting of the colls). Early 1974 complaints on the THD-2 can be summarized a s follows: eight complaints of burned or .Lnged hair, one of other hair damage, one of propertydamage. two of shock, and two of fire, flame or smoke. The THD-2 is no longer in production due to the introduction of new models. For the same fear months in '.974, the Appliance Division recicved 69 .non-routine compla:- -- me H r - " . t e r r e - ' c ; 7 " of tits number est:mated to be in m.c funds cf -. ' -mens us c: April T \ Iu74. Fury-one c: the units involved were returned ur.d examined: of m.ese. 4S were found to have component defects o r mal- G 00416 C a r l Blechschmidt June 12, 1974 Fag * ftmctlona unrelated to loose heating colls; the remaining three contained unspecified heating coll malfunctions. The 69 complaints break down a s follows: 30 complaints o f burned or singed h air, two of other hair damage, one of property damage, ten o f shock, 18 of burned skin, and eight of Are, flame or smoke. In evaluating these sta tistic s. It m ust be emphasized that the conditions complained of, If In fact they occurred, cannot be attributed to coil shorting fo.r the reasons - discussed above: coil arcing cannot cause shock or ignition of flammable m aterials. In the great majority of ca se s, various isolated component defects unrelated to loose heating coll mounting can be found which may have caused the conditions com plained of; in some c a se s we simply do not know what, if anything, went wrong with the unit in the field. Arcing due to coll shorting leaves no traces on the unit. - In addition to the letters described above, we also receive letters complaining of incidents which are not borne out by the condition of the returned dryer (e. g.^, Are o r "nam e" Is complained of, but the dryer shews no sign of heat; "explosion" Is complained of but the dryer is returned intact) or incidents which we do not believe represent safety hazards (e. g . , "blown bouse ftises", where of course other appli ances may have contributed to the occurrence). We do not believe that these a re sufficiently serious to be treated in the same fashion a s the complaints described previously; nonetheless the number thereof is-as follows: for the THD-2 for 1973 ^ and the fir - ' four months of 1974, a total of 21 (representing approximately .0012-. of the num('rr In the hands of consum ers on April 30); for the HD-7 since its Intro duction In August of 1973 through April 30, 1974, a total of 101 (representing approximately .0069% of the number in the hands of consumers cm April 30). Corrective Action In order to estimate the incidence of headng coll short circuiting due to loose mounting of the colls, the Appliance Division subjected both the THD-2 and HD-7 to an energized Impact test. Elghtv units (40 new and 40 used) of each model were dropped one m eter onto a hardwood block In all possible orientations. The incidence of coll shorting was determined by visual observation and by monitoring current draw. The incidence of coll support cord breakage was determined by visual observation. The used units are estimated to have been In the hands of consumers from 3-13 months (THD-2) or 4-10 months (HD-7). A total of six Incidents of coil shorting were observed on the THD-2. and 43 on the HD-7. There was no correlation between coil shorting and unit age or Impact surface. There was no evidence of heacer support cord areo^arc. which means that the short mg w as temporary only: the dryers tested could continue to be uce 1after imoact. There were two incidents of arcing outside the unit .or, ...c HD-7, and none for the THD-2. As we have duumentcd inthc e a rlie r sections of this letter, coll shorting is not hazardous: therefore, we would estimace the number of product units containing a G 00417 Page 5 safety hazard due to such shorting a s none. We estimate that u of April 30, 1974 there were approximately 1,726,000 TH D -2s and 1,463,000 HD*7s In the hands of consumers. Based on the results of the Impact te st described abort, we estim ate that 130,000 THD-2s (7.5%) ancj 756,000 HD-7s (54%) could exhibit temporary cofl shorting; of this number, based on the sam e te st, no THD-2s and only 37,000 HD-7a (2.5%) could exhibit arcing outside the d ry er. Although the shorting is not hazardous, the Appliance Division realized that such ' a condition could be of concern to consum ers who notice it and reflect on the quality of our product. Accordingly, a s a resu lt of a meeting held on May 6, 1974 with engineers of the Consumer Product Safety Com m ission, the following corrective actions were or are being taken with Tegard to the HD-7: 1. The manufacturer has been instructed to add to his present extensive quality control procedures a careful examination of all units produced for excessively loose heater coils; units which exhibit this condition will be scrapped or reworked. T his is now being done. ' 2. A pilot lot of units is now being produced with several improvements, among which Is a repositioning of co lls to maximize the distance between coils. Lf subsequent evaluations show that these changes Improve the quality and safety of the product, the changes will be made to production units a s soon as possible 3. There Is a m ica support In the center of the heater box which Veeps the co ils from hitting each other. Some prototypes are being made with two mica supports rather than one to provide more rigidity. This change will be made . in production urlt3 as soon a s Is possible If evaluation results indicate an improvement in product quality and safety.' Preliminary Investigations In th is area have shown that the additional m ica support Increases the loads required to cause short circuiting from about 60 G's to about 200 G's . A very severe Impact against a haoid generates about 70 G's . 4. . The mica support mentioned above holds the colls In a slot which allows som e movement between the coil and the support. Prototypes arc now being made with holes rather than slots. T his should hold the coils more securely and will become a part of production units as soon a s possible after evaluation. If results show an increase in product quaiicy and safety. No chances to the plastic case rr. terial a re contemplated sir.ee we feel chat case "tlam -ubhr.-'' is not hazardous. In addition, the material presently used has , excellent tr.tricc resistance ch aracteristics. No corrective action is contemplated on the THD-2 since it is no longer being pro- chiccd due to mcrvctinc c. soles.t.n.c. G 00418 G irl Blcchschmidt June 12, 1974 Page 6 In d osin g, w wish to emphasize again that we do not believe that either the THD-2 or the HD-7 contains a defect which would render It a substantial hazard to consum ers using these products. If you have any questions or require any further Information, please feel free to call at your convenience. Very truly yours, JBL/dd G 00419